Bush has asked, on Obama’s behalf, to tap the second half of the $700 billion TARP bailout program.

The first half of TARP was essentially used to stabilize. It’s impossible to know what might have happened if banks hadn’t gotten a $350 billion liquidity injection last year, but certainly it helped bring the financial world back from the brink.

Tarp 2.0 — if it’s spent wisely — has the opportunity to provide a much more visible bang for those hundreds of billions of bucks.

In a letter to Congress today (link to PDF forthcoming), Obama finance guru Larry Summers lays out three priorities for the cash — two directly targeted at stimulating Main Street.

Priority number one remains defensive: No More Lehmans.

Priority number two: Unfreeze credit markets not just for big boys, but for small businesses, municipalities, and consumer lending.

Priority number three: Implementing the foreclosure-prevention tools included in the TARP arsenal.

All of this overlaid with a commitment to greatly increased transparency, oversight, and increased restrictions on executive pay, dividend payouts, and stock buy-back.

In short, Obama is going to have a ton of cash to play with to start bringing visible change and real stimulus from Day 1, and that’s before the $800 billion stimulus package gets rolling.

I think that’s why there’s fairly minimal fretting that the Congressional process isn’t moving fast enough to have the stimulus package waiting on Obama’s desk.