In this year of strange political bedfellows and stranger political outcomes, consider the case of Harry Reid and the tea partiers.
The Senate majority leader is about as loathed a figure as there is in the tea party rank-and-file. The fact that he's up for reelection in Nevada this year leaves him as perhaps the top target of the still-emerging movement.
All three Republicans vying to win the nomination Tuesday to take on Reid, D-Nev., consider themselves tea partiers. And therein rests a potential problem for the GOP that could cost them the chance to take down Reid this year.
The late momentum going into Tuesday's primary is with Sharron Angle, who has sought to claim tea party enthusiasm by endorsing a phasing-out of the Social Security system and a shuttering of the Department of Education.
Recent polls show either of the other two Republicans -- establishment choice Sue Lowden or Danny Tarkanian, the son of former UNLV basketball coach Jerry Tarkanian -- as stronger general-election candidates against Reid in Nevada, a classic purple state these days.
Angle's fiery candidacy is the latest manifestation of the potential for the tea party movement to cut both ways for Republicans. Its vast political energy already defeated the party establishment's choice in Kentucky earlier this month, and helped spark a three-way race for the Senate in Florida.
Now, in Nevada, Democrats hope tea partiers leave Republicans with a weaker general-election candidate against the Senate's top Democrat.
Here are some other big storylines likely to emerge Tuesday, in the single biggest day of voting until Election Day 2010:
Meg Whitman and Carly Fiorina -- favored in the GOP primaries for governor and Senate, respectively -- appear set to top the ticket for Republicans in the Golden State.
The story will be too intriguing to resist: Two highly successful female CEOs, offering a new face for the Republican Party -- and strong chances for the GOP in a heavily Democratic state.
But the only folks not interested in that particular story may be Whitman and Fiorina themselves. The two candidates are not close personally, and neither campaign wants to be saddled with potential baggage from the other candidate's corporate record.
Add to that the likelihood that Whitman and Fiorina will shatter every known campaign spending record in the nation's most populous state, in campaigns that will be largely funded out of their own pockets, and Democrats may not mind running against this particular team.
The political establishment could get another harsh message in Arkansas, with Sen. Blanche Lincoln struggling to hold on to the Democratic Party's nod in a primary run-off against Lt. Gov. Bill Halter.
The race pits organized labor against the Obama White House. Former President Bill Clinton, still a popular figure among Democrats in Arkansas, is trying to drag Lincoln over the finish line.
Either candidate will have an uphill climb in the fall. But it may be Halter who has greater potential in the general election: He can run as a Washington outsider in a year when such candidates are far more popular than incumbents, and he doesn't have a voting record he'd need to defend in the fall.
A bizarre series of revelations will test Sarah Palin's choice for governor of South Carolina.