Eight states will go to the polls today to pick congressional and gubernatorial nominees for the November midterm elections. But there's one race that pretty much everyone will be watching: Mississippi Tea Partier Chris McDaniel's attempt to unseat sitting Sen. Thad Cochran, who is seeking his seventh term in office. In addition to the race conveniently fitting the familiar (if not entirely accurate) Tea Party vs. Establishment theme for the GOP this midterm cycle, the race itself has been unusually salacious, as an ally of McDaniel was caught in a scandal that involved illicit filming of Cochran's comatose wife. 

There are a few speculative scenarios orbiting Tuesday's outcome in Mississippi, but none are expressed so dramatically as Mike Allen's Playbook in Politico: 

PLAYBOOK PREDICTION: The ’14 map may be in for a huge disruption. Our conversations with top Republicans unearthed this scenario:  In today’s primary, Sen. Thad Cochran (R-Miss.) – the GOP senator who is most endangered this cycle -- is forced into a runoff with his tea party challenger, state Sen. Chris McDaniel. (There’s a 50-percent threshold, and a third candidate in the race.) Cochran doesn’t have the stamina or political agility for the frantic three-week runoff (June 24) that follows, and he LOSES. Then Mississippi – which last voted D in a presidential race in 1976 -- is IN PLAY, complicating GOP majority hopes.

Conventional wisdom says that Cochran, 74, needs to hold onto the nomination in order to keep his seat "safe" for Republicans in 2014. The GOP, of course, is attempting to gain a majority in the Senate, but a McDaniel win would ensure that the party would have to invest more resources for November in what would become a suddenly competitive race, even as the party is also working hard to target "vulnerable" Democratic incumbents in several states. The fact that McDaniel has been tangentially linked to a blogger who is currently in jail for allegedly filming Cochran's wife doesn't help the GOP in this case. Tea Party groups have invested heavily in McDaniel's primary challenge. As Slate's Dave Weigel outlined, the polling on this race in Mississippi is sparse and pre-blogger scandal, meaning that there's not a ton of reliable polling to go on heading into today's votes. 

If Cochran loses, then Mississippi would also have to contend with a huge lost of seniority in the Senate: Cochran would take over the Appropriations Committee if Republicans gain control of the Senate. His influence has come in handy before for the state, as the Daily Journal reported: following Hurricane Katrina, Cochran was able to secure substantial recovery funds for his state. 

But McDaniel is pitching himself against that sort of congressional leadership and competence, essentially arguing that Mississippi's conservative residents should have the most conservative senator in the nation. And that in a crowded field of Republicans running as fast as they can to the right, he's still in the lead. The New York Times has more: 

Mr. McDaniel’s main campaign argument against Mr. Cochran, 76, is that the incumbent has been too willing to work with Democrats and not aggressive enough in opposing President Obama. “Mississippi is the most conservative state in the republic. It deserves the most conservative senator in the republic,” Mr. McDaniel, 41, said Saturday at a rally on the Gulf Coast.

Also primary-ing today: Alabama, Iowa, Montana, New Jersey, New Mexico, and South Dakota all have Senate races. And gubernatorial primaries will kick off in Alabama, Iowa, New Mexico, South Dakota, and California.