Is Bush the third candidate in tonight's debate?

Tonight's first debate between President Obama and Mitt Romney may well include a third politician: George W. Bush.

Obama rarely mentions Bush by name any more, but frequently talks about inheriting an economic crisis from his predecessor -- and that Romney's tax-cutting, low-regulation policies are virtually the same.

"We just tried that in the decade before I became president," Obama said this week in Las Vegas. "It didn't work. Top-down economics never works. We don't need to double down on the same trickle-down policies that got us into this mess in the first place."

Romney also rarely mentions Bush by name, but may have to grapple with the 43rd president's legacy during tonight's debate with Obama in Denver.

Still, Romney and his aides say the issue is Obama's stewardship of the economy, and it is still struggling.

"The two names on the ballot are Mitt Romney and Barack Obama and there's a very clear choice between the two," said Romney senior adviser to Kevin Madden to Politico. "This last phase of the campaign is going to be about how we set the country on a better course going forward."

The Denver debate starts at 9 p.m. ET, and you can follow all the action at USA TODAY's website.