KANSAS CITY, Mo. - According to a new poll, Missouri's incumbent democratic senator Claire McCaskill is in trouble in November.
It shows McCaskill losing no matter which Republican wins in next week's primary.
The race has heated up, with Sarah Palin throwing her weight behind former state treasurer Sarah Steelman.
The 2008 vice-presidential candidate even made an appearance in a new campaign commercial that started running Monday.
In the ad, Palin says of Steelman, "Sarah is an economist who defends our tax dollars, like a momma grizzly defends her cubs."
Patrick Tuohey, a spokesman for the Steelman campaign, said Palin's endorsement carries a lot of weight.
"I think it'll excite an awful lot of people who, when they see Sarah Palin, know what that means and understand what her endorsement carries," he said. "I imagine it'll excite a lot of people in the base."
Steelman is locked in a Republican primary battle with Congressman Todd Akin and businessman John Brunner.
Despite a 16-point spread between the three in the new poll, an outside political consultant said it's still anyone's race.
"The point is, is that it is still wide open," said Republican political consultant Christian Morgan of Axiom Strategies.
Morgan said the race is so fluid that the winner could depend on which candidate gets out the best message in these final days.
"Who has built the trust of going in, not just to beat Claire McCaskill, to actually go to Washington and pass some common sense legislation? Whoever's built that narrative is going to win," Morgan predicted.
While Steelman got the Palin endorsement, the biggest for Brunner is the U.S. Chamber of Commerce.
Akin's biggest endorsement is from former presidential candidate Mike Huckabee.
Morgan outlined a winning scenario for each candidate:
Brunner can win if he holds his lead in the polls.
Brunner and Steelman are attacking each other so much that undecideds could break for Akin, and he'd come up from third place.
Brunner and Akin are both from St. Louis, so if they split that vote, Steelman could win out-state and Springfield and take the nomination.
The new poll shows that Brunner leads McCaskill by 11 percent. The gap is closer when McCaskill is pitted against Steelman or Akin.
The St. Louis Post-Dispatch and KMOV-TV paid for the new poll, which included 625 registered voters and was done over the phone last week.
McCaskill's campaign responded with a statement Monday afternoon.
"While a lot of polls show us both up and down, we know that we have the best operation, so the only poll that matters is when the voters speak on November 6," said spokesman Erik Dorey.