With just 15 days until the midterm elections, both parties are trying to fire up their supporters to make sure they make it to the polls. But this year the Republicans and Democrats are also contending with Tea Party groups, one of which is staging a cross-country tour to push its favored candidates to victory.
CBS News correspondent Ben Tracy reports a Tea Party Express bus is embarking today on a 19-state trip, setting off from Nevada (where activists are holding a rally aimed at knocking off Senate Majority Leader Harry Reid), and in the next 15 days will roll into 30 different cities, finishing in New Hampshire.
According to, 18 percent of Americans call themselves Tea Partiers - including some who have never been politically active before. By one estimate, the growing movement is backing 138 candidates in the midterms.
Tea Party supporters advocate for a drastically smaller federal government and for politicians to be held more accountable.
"We're not scary, we're not extremists, but you're responsible to the American people and we're going to make sure you are," said Charlene Bybee, one Tea Party supporter.
The Tea Party's number one target: Senator Harry Reid. Tea Party Express, a Sacramento-based group, has spent more than $1 million in Nevada trying to defeat him and get their candidate, Sharron Angle, elected.
Polls show the two are basically tied, so the bus is there to rally the troops. Also planning to appear in Nevada today with the GOTV message: Sarah Palin, whose endorsements have helped 25 candidates win in GOP primaries.
At a rally in California Friday, Palin told the crowd, "The momentum is with us, but now is not the time to let up."
"This Tea Party Express bus tour is about getting out the vote - really ginning up that anger," Politico's Ken Vogel told CBS News.
It will eventually roll through Delaware (where Tea Party favorite Christine O'Donnell is trailing Democrat Chris Coons by 20 points. O'Donnell is blaming the Republican Party for not giving her campaign enough help.
"We're hoping that the National Republican Senatorial Committee will help us," she said on ABC's "This Week With Christiane Amanpour," but it's two-and-a-half weeks left, and they're not."
President Obama was also on the campaign trail, traveling with the more popular First Lady to Ohio to fire up Democrats.
"This is about more than just politics," Michelle told the crowd of 35,000. "It's about whether or not we, as a people, can move forward through times of challenge and cynicism and frustration."
The president preached the Democrats' message that a Republican victory would mean a return to failed policies of his predecessor: "It is up to you to tell them, 'We do not want what they are selling. We've been there before, and we are not going back.'"
"This message is not just about Ohio," said CBS News political analyst John Dickerson, "but to send a message to Democrats everywhere that if they can turn out 35,000 here, Democrats everywhere have to get out on Election Day - or before, in those states with early voting."
An AP/Knowledge Network poll released Sunday showed that a quarter of those who voted in 2008 are planning or considering to vote for the opposite party - expressing broad dissatisfaction with both parties.
But while other polls suggest an "enthusiasm gap" (meaning Republicans are more fired up to go to the polls), the new poll shows party support is stronger among Democrats (71 percent of Obama voters say they would vote for the Democratic candidate, while 6 percent "lean" Democratic) than Republicans (7 percent of McCain voters plan to vote for the Republican, while 67 percent are leaning to the GOP).
On Sunday President Obama's spokesman reversed his earlier prediction that Democrats would lose control of the House.
"Come election night, we'll retain control of both the House and the Senate." White House Press Secretary Robert Gibbs predicted on NBC's "Meet the Press."