In a curious election twist, Tea Party Express, one of the movement's most powerful national groups, has endorsed Idaho Rep. Walt Minnick, a Democrat, over his GOP challengers. State Tea Partiers were outraged by the move, especially since Sarah Palin has already endorsed Minnick's leading rival. (Watch Democrat Walt Minnick talk about the health care bill he opposed.) Here's a brief look at the controversy:

Who is Walt Minnick?
A Democratic congressman representing Idaho's 1st district, the 67-year-old began his political career in the Nixon Administration, where he helped create the Drug Enforcement Administration (DEA). He resigned in protest at Nixon's actions during the Watergate era, then spent decades in the private sector, until he ran for office in 2008. This is his first term in the House of Representatives.

Why is the Tea Party Express backing him?
A so-called "Blue Dog Democrat," Minnick voted against health care reform, the stimulus bill, and cap-and-trade legislation. The anti-tax Club for Growth gave him a perfect 100 percent score last year. Tea Party Express strategist Sal Russo tells The Daily Caller that it's important to support Democrats like Minnick who "are willing to stand up to Pelosi and Reid," especially when it comes to taxes, spending, and Big Government.

Does everyone buy that reasoning?

No. Minnick's leading GOP challenger, Vaughn Ward, says he's baffled by the decision and disturbed that Tea Party Express "didn't consult anyone in Idaho." Another Tea Party activist agrees that "befuddled" Republicans and Idahoans deserve a better explanation for this "bizarre meddling." The Huffington Post's Sam Stein says that, "on the surface, it would appear that the Tea Party Express put Minnick on its support-list for the sole purpose of having a token Democrat."

Why would Tea Party Express endorse a "token Democrat"?
So it would be seen as an independent group, rather than a GOP puppet. The group has been accused of being a fund-raising tool for Republican political operatives, especially after it published a list of exclusively Democratic "targets" for the November election

Has Tea Party Express endorsed any other Democrats?
No. However, Mark Williams, the talk radio host who chairs the Tea Party Express, said the group had planned to run TV ads in support of Rep. Bart Stupak (D-MI), before Stupak voted for the final version of the health care reform bill.

Is Minnick happy about the endorsement?
Yes. Tea Partiers are "just ordinary folks who think the government ought to balance this budget," Minnick told CNN. "There's nothing very radical about that, so I'm pleased to have their endorsement." His spokesman admitted that Minnick is a little concerned that the endorsement could make some Democrats wary, but that "Walt is not in the habit of turning down support."

Sources: Daily Caller (2), CNN, Huffington Post, Washington Post, Hot Air, Politico, Wall St. Journal, CQ