Thursday night on her Facebook page, she endorsed Doug Hoffman, the Conservative Party candidate for the Nov. 3 special election in New York's 23rd congressional district.
"Unfortunately, the Republican Party today has decided to choose a candidate who more than blurs the lines, and there is no real difference between the Democrat and the Republican in this race," Palin wrote.
Click here to read Palin's full statement.
Expect even more chatter about this race being a fight for the future of the GOP; conservative vs. moderate, etc.
This is the seat that was held for years by former Rep. John McHugh, a moderate Republican who is now President Obama's Army Secretary.
Moderate Republican Dede Scozzafava was favored to win over Democrat Bill Owens, until Hoffman began gaining some steam and splitting the Republican vote.
Hoffman was also endorsed Thursday by Dick Armey; Fred Thompson has also backed him and the conservative Club for Growth has run ads on his behalf (and calling both the Democrat and Republican "liberals"). For her part, Scozzafava has the support of the National Republican Congressional Committee and Newt Gingrich.
The latest polling (Siena, 10/15) in the district, which covers most of northern New York State, shows the Democrat Owens in the lead with 33 percent (up 5 points from Siena's Oct.1 poll), the Republican Scozzafava with 29 (down 6) and Hoffman with 23 (up 7).
What's more important is that among Republicans, Scozzafava only gets 40 percent with Hoffman getting 27 percent. Hoffman leads among independents with 31 percent. Owens gets 28 percent of independents and Scozzafava 24 percent.
Conservatives are looking at this as a prime opportunity to derail a moderate and make a statement that the GOP should move to the right, not to the center.
However, given that this is a moderate district (Obama won with 52 percent of the vote in 2008, Bush with 53 percent in 2004 and former Rep. McHugh repeatedly won easily as a moderate), a third-party conservative candidate has a slim chance of actually winning the seat.
What's more likely: Hoffman derails Scozzafava's chance at winning, handing the Democrat Owens a victory and House Democrats another seat on Nov. 3.
While that may embolden conservatives to try to derail moderate Republicans across the country, this election may not prove a major indicator of the direction of the GOP.
There are still many Republican leaders that are pushing for moderates to be part of the fray, including NRSC Chairman Sen. John Cornyn, R-Tex., who has recruited such moderates as Charlie Crist in Florida and Mike Castle in Delaware to run for Senate next year, as well as Gingrich.
In his endorsement of Scozzafava, Gingrich wrote: "I have learned that if America wants a conservative majority in Washington, parts of that majority are going to disagree. I was elected Speaker because a number of moderates voted for me. They gave us control of the House for the first time in forty years, allowing us to balance the federal budget, cut taxes and reform welfare for America... My number one interest is to build a Republican majority. If your interest is taking power back from the Left, and your interest is winning the necessary elections, then there are times when you have to put together a coalition that has disagreement within it. We have to decide which business we are in. If we are in the business about feeling good about ourselves while our country gets crushed then I probably made the wrong decision."
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Steve Chaggaris is CBS News' Political Director. You can read more of his posts in Hotsheet here.