Two states could have Tea Party upsets on Tuesday, and observers are torn as to which is the more likely scenario.

In New Hampshire, Republican Senate candidate Ovide Lamontagne is trying to ride the wave of Tea Party upsets by casting his campaign in the mold of come-from-behind winners Joe Miller in Alaska and Sharron Angle in Nevada.

In Delaware, Tea Party-backed Senate candidate Christine O'Donnell got a boost Thursday when former Gov. Sarah Palin (R) endorsed her.

O’Donnell is challenging party-backed Rep. Mike Castle in the Republican primary, and Palin’s blessing could give her the jolt she needs.

Palin also has something at stake in New Hampshire, where she's backing Kelly Ayotte in the Senate primary.

Most of the attention has been focused on Delaware, but some observers say New Hampshire may have the race to watch Tuesday. 

Lamontagne faces two better-known and better-funded Republicans in the Senate primary in the form of Ayotte and self-funded Bill Binnie. But Ayotte and Binnie have been spending their cash ripping each other to shreds on the airwaves, and observers say Lamontagne has been the short-term beneficiary.

"I think people understand that these races are national in scope and we need to elect true conservatives," Lamontagne told The Hill. "That's why you've seen the enthusiasm building."

Businessman Jim Bender is also self-funding his campaign, and while most don't believe he has a real shot of winning, he could factor into the eventual outcome, depending on the share of the vote he ends up with.

Lamontagne is talking up his support from conservative talk-radio host Laura Ingraham, whom he called "a strong supporter of our campaign who laid out the case on her show as to why Sarah Palin made the wrong choice in this primary."

The candidate also highlighted support from RedState's Erick Erickson, who questioned on his blog Wednesday why money and energy was focused on O'Donnell in Delaware and not Lamontagne in New Hampshire.

Ayotte certainly has some conservative backing. Aside from Palin, she was endorsed by the pro-life Susan B. Anthony List and has the support of Sen. Tom Coburn (R-Okla.) and former Sen. Rick Santorum (R-Pa.). 

Still, University of New Hampshire pollster Andy Smith said a Lamontagne upset is well within the realm of possibility. During Lamontagne's 1996 run for governor he surged from more than 20 points back before the primary to capture the nomination.

A Lamontagne adviser says the campaign has no plans to go negative ahead of Tuesday —apparently seeing the negative between Ayotte and Binnie as the candidate's best shot.

As for support from the Tea Party Express, which has poured hundreds of thousands of dollars into GOP primaries in Nevada, Colorado and Alaska this cycle, it won't be forthcoming.

Spokesman Levi Russell told The Hill that his group is focused squarely on Delaware ahead of Sept. 14 and won't spend any resources in New Hampshire.

"It's definitely on our radar," Russell said of New Hampshire's Senate primary. "But we are still focused on Delaware."