It was unclear whether Obama would support the current proposal if it doesn't include his provisions, and he said, he would only go back to Congress to vote if the vote is close.
"If we get a consensus and everybody is popping champagne -- then I will probably be going back to campaign with folks who are having a tough time in places like Ohio, and Michigan and Pennsylvania," Obama said Tuesday. "If this ends up being a close vote or a vote where the outcome is an open question then obviously this is a top priority."
Republican presidential candidate John McCain may hold the key to the passage of the administration's unpopular $700 billion bailout in Congress.
If McCain doesn't vote for the administration's plan, some Republican and Democratic congressional leaders told ABC News the plan won't pass.
"If McCain doesn't come out for this, it's over," a top House Republican told ABC News' George Stephanopoulos.
A Democratic leadership source said that White House Chief of Staff Josh Bolten has been told that Democratic votes will not be there if McCain votes no -- that there is no deal if McCain doesn't go along.
McCain has expressed concerns about Treasury Secretary Henry Paulson and Federal Reserve Chairman Ben Bernanke's plan, which would amount to costing the American taxpayer the price of two Iraq wars.
The Republican presidential candidate has suggested the original proposal lacks sufficient oversight, and he has said whatever plan emerges should protect family savings, homes and student loans, and should eliminate obscene CEO compensation packages.
McCain said this week that any company that receives government aid should not be compensated more than $400,000 -- the highest-paid government employee.
McCain spokesman Tucker Bounds told ABC News' Jake Tapper that McCain has not made a decision one way or another.
"John McCain has been very clear that he has certain reservations about the details of the agreement that has been released at last notice," Bounds said. "There is no final agreement to review, but when there is John McCain will weigh in responsibly and appropriately."
Administration officials went to Capitol Hill Tuesday to urge Congress to pass the bailout package quickly, arguing the nation's economy is teetering on the brink of a major recession.
Some senior Democrats on Capitol Hill have voiced concern that McCain would continue to oppose the Bush administration's plan as a way to position himself as a critic of Wall Street and the Bush administration.
If McCain doesn't vote for the legislation, other Republicans might follow suit, leaving the Democratic-led majority to fight in Congress to pass the risky bailout plan.
However a Democratic congressional leadership source told ABC News' Jake Tapper that Paulson went so far as to assure Democratic leaders that McCain "won't be a problem" -- in other words that McCain will vote for the proposal.
ABC News' George Stephanopoulos, Jake Tapper, Z. Byron Wolf, Sunlen Miller, Viviana Hurtado and Ann Compton contributed reporting to this story.