Donald Trump's supporters like to visualize his campaign as a roaring freight train, but the accurate metaphor might be a leaky boat: Trump is rapidly sinking in the polls, and longtime GOP loyalists are jumping ship every day.
The defections began in earnest on May 3rd – the day Trump won the Indiana primary and RNC chair Reince Priebus declared him the party's presumptive nominee – but they've picked up in the wake of an underwhelming convention and series of increasingly damaging missteps.
On August 8th, more than 50 Republican national security officials circulated a letter declaring they would not vote for Trump. "From a foreign policy perspective, Donald Trump is not qualified to be President and Commander-in-Chief," the authors wrote. "Indeed, we are convinced that he would be a dangerous President and would put at risk our country's national security and well-being."
Two days later, the Clinton campaign rolled out endorsements from nearly 50 more high-profile Republicans – officials who worked in the Reagan White House and both Bush administrations, plus donors and longtime party loyalists.
Below is a running tally of all the high-profile Republicans (defined here as elected or appointed officials, or those who have worked in government) who have so far refused to back the GOP nominee. We'll continue to update as more roll in. (Last updated September 7th.)
–Massachusetts Gov. Charlie Baker
–Jeb Bush: "Donald Trump has not demonstrated that temperament or strength of character. He has not displayed a respect for the Constitution. And he is not a consistent conservative. These are all reasons why I cannot support his candidacy."
–Florida Rep. Carlos Curbelo
–Illinois Rep. Bob Dold
–South Carolina Sen. Lindsey Graham
–Doug Elmets, Reagan White House spokesman
–Retired Army Col. Peter Mansoor
–Former New Jersey Gov. Christine Todd Whitman
–Illinois Sen. Mark Kirk: "While I oppose the Democratic nominee, Donald Trump's latest statements, in context with past attacks on Hispanics, women and the disabled like me, make it certain that I cannot and will not support my party's nominee for President regardless of the political impact on my candidacy or the Republican Party."
–Former South Dakota Sen. Larry Pressler: "This election is starting to sound like the German elections in [the late 1920s]... This is a very dangerous national conversation we're slipping into."
Trump "has not displayed a respect for the Constitution. And he is not a consistent conservative." —Jeb Bush
–Maryland Gov. Larry Hogan
–Richard Armitage, deputy secretary of State under George W. Bush
–Brent Scowcroft, national security adviser to George H.W. Bush and Gerald Ford, White House aide to Richard Nixon and George W. Bush
–Jim Cicconi, aide to Reagan and George H.W. Bush
–Henry Paulson, former Treasury Secretary under George W. Bush
–Kori Schake, former George W. Bush national security official
–Tony Fratto, a former deputy press secretary to President George W. Bush
–Kenneth Adelman, former director of the Arms Control and Disarmament Agency
–Nevada Sen. Dean Heller: "He did a lot of damage. It's very difficult for him, as far as I'm concerned, to recover from his previous comments. I'll give him a chance, but at this point, I have no intentions of voting for him."
–Patrick M. Cronin, assistant administrator of the Agency for International Development under George W. Bush
–Philip Levy, former member of President George W. Bush's Council of Economic Advisers
–Andrew Natsios, special envoy to Sudan under George W. Bush
–John Noonan, former House Armed Services Committee staffer and adviser to Mitt Romney and Jeb Bush
–Charles Fried, U.S. solicitor general under President Reagan: "Though long a registered Republican, this will be the third consecutive presidential election in which my party forces the choice between party and, in John McCain's words, putting America first. Sarah Palin, McCain's erratic and surely regretted choice as running mate, in her voluble and opinionated ignorance was an early precursor of Donald Trump. It was the spirit of Sarah Palin and those who cheered her on that animated the subsequent defeat of such traditional Republicans as Bob Bennett in Utah, Dick Lugar in Indiana, and Eric Cantor in Virginia. Many who survived only did so by pretending to positions they did not hold. There was no more transparent pretender than Mitt Romney in 2012. Now those same forces have given us Donald Trump, whose presumptive presence at the head of the Republican ticket disgraces not only the party but the nation. You sow the wind and reap the whirlwind. It is to Romney's credit that this year, like John Paulson and George Will, he is standing up against the brutal, substantively incoherent, and authoritarian tendencies of Donald Trump."
–Peter Wehner, who served in the last three Republican administrations
–Ted Cruz: "I am not in the habit of supporting people who attack my wife and attack my father."
–New York Rep. Richard Hanna: "I find Trump deeply flawed in endless ways."
–Pennsylvania Rep. Charlie Dent
–Sally Bradshaw, former aide to Jeb Bush
–Maria Comella, former aide to Chris Christie: "Donald Trump has been a demagogue this whole time, preying on people's anxieties with loose information and salacious rhetoric, drumming up fear and hatred of the 'other.'"
–Rudy Fernandez, former special assistant to President George W. Bush
–Illinois Rep. Adam Kinzinger
–Former Montana Gov. Marc Racicot: "I cannot and will not support Donald Trump for president."
–Former Minnesota Rep. Vin Weber: "I won't vote for Trump… I can't imagine I'd remain a Republican if he becomes president."
–Former New Hampshire Sen. Gordon Humphrey: "I am ever more confirmed in my belief that Trump is a sociopath, without a conscience or feelings of guilt, shame or remorse."
–Greg Mankiw, former chair of George W. Bush’s Council of Economic Advisers
–Virginia Rep. Scott Rigell
–Former Minnesota Gov. Arne Carlson
"I am not in the habit of supporting people who attack my wife and attack my father." —Ted Cruz
–Former Deputy Attorney General Donald Ayer
–John Bellinger III, former legal adviser at the State Department and National Security Council
–Robert Blackwill, former deputy national security advisor at the the White House
–Michael Chertoff, former secretary of Homeland Security
–Eliot Cohen, former counselor to the State Department
–Eric Edelman, former under secretary of defense for policy
–Former deputy national security advisor Gary Edson
–Former deputy Homeland Security advisor Richard Falkenrath
–Peter Feaver, former senior director for strategic planning on the National Security Council
–Richard Fontaine, former National Security Council associate director for Near East affairs
–Jendyi Frazer, former U.S. assistant secretary of State for African affairs and National Security Council senior director for African affairs
–Aaron Friedberg, former deputy assistant for national security affairs in the office of the vice president
–David Gordon, former State Department director of policy planning
–Michael Green, former National Security Council senior director for Asian affairs
–Former State Department chief of staff Brian Gunderson
–Paul Haenle, former director for China and Taiwan on the National Security Council
–Former CIA Director Michael Hayden
–Carla Hills, former HUD secretary under Gerald Ford and former U.S. trade representative
–John Hillen, former assistant secretary of State for political-military affairs
–William Inboden, the National Security Council's former senior director for strategic planning
–Reuben Jeffery III, former under secretary of State for economic energy and agricultural affairs
–James Jeffrey, former deputy national security adviser
–Ted Kassinger, former deputy secretary of Commerce
–David Kramer, former assistant secretary of State for democracy, human rights, and labor
–James Langdon, chairman of George W. Bush's foreign intelligence advisory board
–Peter Lichtenbaum, former Department of Commerce assistant secretary for export administration
–Mary Beth Long, former assistant secretary of Defense
–Clay Lowery, former assistant secretary for international affairs at the Treasury Department
–Former Associate Attorney General Robert McCallum
–Richard Miles, former National Security Council director for North America
–Andrew Natsios, former administrator for USAID
–John Negroponte, former director of national intelligence, deputy secretary of Dtate, and UN ambassador
–Meghan O'Sullivan, former deputy national security adviser on Iraq and Afghanistan
–Dan Price, former deputy national security advisor for international economic affairs under George W. Bush
–Former Secretary of Homeland Security and Pennsylvania Gov. Tom Ridge
–Nicholas Rostow, special assistant to Presidents Reagan and George H.W. Bush for national security affairs and legal adviser to the National Security Council under Colin Powell
–Kori Schake, former director for defense strategy and requirements on the National Security Council, and deputy director for policy planning inside the State Department
–Kristen Silverberg, former U.S. ambassador to the European Union and assistant secretary of State for international organization affairs
–Stephen Slick, former director for intelligence programs for the National Security Council
–Shirin R. Tahir-Kheli, former senior advisor to Secretary of State Condoleezza Rice
–Former Deputy Secretary of Defense and onetime Ambassador to NATO William Howard Taft IV
–Former Deputy Attorney General Larry Thompson
–William Tobey, former deputy administrator of the Department of Energy's National Nuclear Security Administration
–John Veroneau, former deputy U.S. trade representative
–Kenneth Wainstein, Homeland Security advisor to George W. Bush
–Matthew Waxman, former deputy assistant secretary of Defense
–Dov Zakheim, former under secretary of Defense
–Roger Zakheim, former deputy assistant secretary of Defense
–Philip Zelikow, former counselor for the Department of State and executive director of the 9/11 Commission
–Robert Zoellick, former president of the World Bank, U.S. trade representative and deputy secretary of State: "None of us will vote for Donald Trump."
–Lezlee Westine, former aide to George W. Bush: "Trump falls short in terms of the character and behavior needed to perform as president. This defect is crippling and ensures he would fail in office."
–Former Michigan Gov. William Milliken
–Frank Lavin, Ronald Reagan's White House political director
–Maine Sen. Susan Collins: "I have become increasingly dismayed by his constant stream of cruel comments and his inability to admit error or apologize. But it was his attacks directed at people who could not respond on an equal footing — either because they do not share his power or stature or because professional responsibility precluded them from engaging at such a level — that revealed Mr. Trump as unworthy of being our president."
–Florida Rep. Ileana Ros-Lehtinen
"I find Trump deeply flawed in endless ways." —New York Rep. Richard Hanna
–Ruben Alvarez, former policy advisor to Arizona Gov. Jane Dee Hull
–Retired Major General Donna Barbisch
–Jim Cicconi, aide to Ronald Reagan and George H.W. Bush
–Former Minnesota Sen. David Durenberger
–Scott Evertz, former director of the Office of National AIDS Policy under George W. Bush
–Fred Goldberg, Jr., former IRS commissioner
–David Gross, former U.S. coordinator for international communications and information policy
–Cindy Guerra, former regional deputy attorney general for Florida
–Carlos Gutierrez, Commerce secretary under George W. Bush
–Matt Higgins, former press secretary to Rudy Giuliani
–Former State Department official Richard Holwill
–Former Utah state legislator and retired Brigadier General David Irvine
–James Kunder, former assistant administrator for Asia and the Near East at USAID under George W. Bush
–Former General Counsel of the Navy Alberto Mora
–Former Maryland Rep. Connie Morella
–Retired Major General Gale Pollock
–William Reilly, EPA administrator under George H.W. Bush
–William Ruckelshaus, EPA administrator under Presidents Reagan and Nixon
–Former Special Counsel for the Department of Justice William Sanchez
–Former Connecticut Rep. Christopher Shays
–Timothy Stratford, former assistant U.S. trade representative for China
–Pete Teeley, press secretary for George H.W. Bush and former ambassador to Canada
–Daniel Twining, former State Department policy planning staff under George W. Bush
–Ashley Tellis, former special assistant to George W. Bush and senior director for strategic planning and Southwest Asia
–Paul Wolfowitz, deputy secretary of defense under George W. Bush administration
–Charles Fried, solicitor general under Ronald Reagan