White House spokesman Tony Fratto said the president was calling senators on the upcoming vote, but not House members.
"We're going to keep working today and we're going to work tomorrow when the House takes it up," Fratto said.
Sens. Barack Obama and John McCain left the campaign trail so they could return to Washington in time for the vote. Democratic vice presidential candidate Sen. Joe Biden will also be in Washington for the vote.
It will be the first time the presidential candidates are back in Washington since last week, when McCain suspended his campaign to concentrate on the economic crisis, when both he and Obama met with President Bush on the issue.
Shortly after that meeting, the bailout deal unraveled amid bitter accusations that each side had politicized the issue and contributed to the shocking House vote to defeat it.
Bailout strategists hope that approval by the Senate will put additional pressure on the House to finally approve the bill.
McCain projected confidence on the bill's passage during a speech at the Harry S. Truman Library in Independence, Mo. He said Congress has "awakened to the danger," and predicted doom if the bill should fail.
"If the financial rescue bill fails in Congress yet again," McCain said, "the present crisis will turn into a disaster."
Obama, addressing a rally in LaCrosse, Wis., said Congress shouldn't delay any longer.
"To the Democrats and Republicans who have opposed this plan, I say this -- step up to the plate, do what's right for the country, even if it's not popular, because the time to act is now," Obama said.
Squabbling over the $700 billion bailout can't end soon enough for Jack Welch, the former CEO and chairman of General Electric, who warned on "Good Morning America" today that "every day we wait, every minute we wait, increases the depth of the downturn in the economy and the length of it."
Welch told "GMA" that whatever gets passed must be passed soon and must pass two tests: "It must free up credit and increase confidence."
The former G.E. titan dismissed the significance of Tuesday's stock market surge.
"We're talking about the wrong thing when we're talking about markets, the stock market's up, the stock market's down," Welch told "GMA." "The credit market is tighter [Tuesday] than it was Monday, than it was last Friday. So it continues to tighten. And that's the game. It's all about credit and confidence."
Welch said the effects of the tighter credit are already being felt by ordinary Americans in the loss of jobs, as well as businesses.
"The job thing has already started. The job thing is running away on us," Welch said, adding, "The fourth quarter could be down significantly."
Welch said a conversation with a banker illustrated how tight the credit market has become.
"He can give mortgages, but he's so selective in giving them that he's holding back cash to be sure of any eventuality. These credit markets are tighter than we have seen," Welch said.
In addition, he said, "We're seeing the lowest consumer spending in 20 years, so this is really tough."
The Associated Press and ABC News' Sunlen Miller and Bret Hovell contributed to this report.