His campaign added the stop to his schedule late Tuesday. With less than one day's notice, McCain supporters lined up outside the Truman Presidential Library.

"They asked me, 'do you want to go to a John McCain event tomorrow?,' and I'm like, 'well yeah, sure,'" voter Kevin Lawson said.

Only about 100 people got inside when doors opened after 9 a.m. Everyone else waited outside hoping for a glimpse of McCain.

"I'm not sure which way I'm going yet," voter Michael Harris said.

As Congress debated the economic bailout, McCain talked about the economy.

"If the financial rescue bill fails in Congress yet again, the present crisis will turn into a disaster," McCain said.

A Survey USA poll says McCain has a two-point lead in Missouri. A Gallup poll has candidate Barack Obama leading by four points.

"Missouri is a bellwether state," Jack Johnson of the Missouri McCain campaign said. "It is a swing state and without Missouri I don't think Senator Mccain can go into the presidency."

As for the Democratic party, Michelle Obama rallied Missouri voters Wednesday afternoon in Kansas City.