Sen. Thad Cochran (R-Miss.) at a pre-election day rally at the Mississippi Agriculture and Forestry Museum in Jackson, Miss., on Monday. (Joe Ellis/AP)
Chief correspondent

Of all the Republican senators who drew tea party opponents in this election cycle, Sen. Thad Cochran (Miss.) seemed particularly ill-prepared for the challenge from state Sen. Chris McDaniel. He was by most measures the most vulnerable incumbent of them all — primed for an upset.

For starters, he symbolized Washington at a time when voters — Republicans and Democrats alike — are disgusted with Washington. Beyond that, he embodied everything that tea party activists say they are fighting against: He is a proud appropriator known for pork-barrel spending and a compromiser too willing to cut deals with Democrats.

Cochran, 76, is old-school in his style. He is courteous and low-key, not one to brag or draw undue attention to his work, and he’s nonconfrontational. He is well respected inside the Senate and has been well appreciated at home. All of that left him susceptible to a challenge from the hard-charging conservative McDaniel, 42, whom he will face in a runoff election on June 24 that is likely to be an even nastier fight than the primary contest.

That Cochran didn’t fully understand how his party has changed was evident even by his own admission. In February, he told some Mississippi reporters, “The tea party, you know, is something I don’t really know a lot about.” That may have been an honest statement, but it was also astonishing and impolitic.

It was all the more surprising given the attention the tea party has gotten over the past five years, the fact that Cochran had seen other Republican lawmakers knocked out by tea party challengers and the reality that he was one of half a dozen GOP senators with tea party opponents.

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As a candidate, Cochran was not at the top of his game. Over the past few weeks, as the race received more and more national attention, he sometimes stumbled during his interactions with the news media, offering answers that did not respond directly to the questions posed. More than one reporter mentioned this in stories over the past week, enough to draw concern from some of Cochran’s allies.

The six-term senator told me last week that he had strongly considered not seeking reelection. “I thought it was time for me to retire,” he said. “I thought I’d served long enough.” He said he ran because people told him that Mississippi needs him.

Cochran struggled with his message. He consistently emphasized his long service to the state and the influence that comes with it and with the experience and knowledge he has accumulated. He told an audience last week that if he were returned for a seventh term, he would make sure Mississippi got its fair share of federal funding.

That message long has worked in Mississippi, which has had a tradition of long-serving members of Congress who have assiduously looked after the state and made certain that it got perhaps more than its fair share of federal facilities, contracts and money. But it has lost its resonance with many in the new Republican Party.

If Republicans win back the Senate in November, Cochran would be in line to chair the Appropriations Committee. But to emphasize that he understands the new tea party Republican Party, he was telling audiences in the campaign’s final days that he would use that chairmanship to make sure Washington didn’t spend too much money.

The Mississippi race began to attract the attention it deserved only after a bizarre incident in April. Cochran’s wife, Rose, who has dementia, has been in a nursing home for more than a decade. A blogger is accused of taking photos of her in the facility and posting them on the Internet.

That blogger and three other men — all supporters of McDaniel — have been arrested. The investigation is ongoing. McDaniel has denied any involvement, although he and his campaign staff mishandled questions about what they knew and when they knew it.

The episode certainly hurt McDaniel. Without it, it’s possible that he would have gotten the 50 percent-plus-one needed to avoid a runoff. But it’s just as interesting that Cochran still could not win outright, even with the inquiry clouding McDaniel in the final weeks of the contest.

McDaniel’s campaign has benefited from a huge infusion of money from outside conservative groups. They poured about $5 million into the state to help him, and they are likely to reload because of the runoff. Cochran remains the last hope the tea party groups have to defeat a Senate incumbent and salvage what has otherwise been a series of springtime victories for the party establishment.

Cochran was helped enormously by the Mississippi establishment, led by former governor Haley Barbour and two of his nephews. Henry Barbour runs the super PAC helping Cochran, and Austin Barbour has been one of the guiding strategists on Cochran’s campaign, along with Stuart Stevens, a Mississippian who was Mitt Romney’s chief strategist in the 2012 presidential campaign.

The Barbour team recognized that complacency was Cochran’s worst enemy — complacency among Mississippi voters. In a series of tweets and statements, Henry Barbour began to sound the alarm, warning that the race was extremely close and that Cochran could lose if his supporters didn’t turn out to vote. That may have been just enough to stave off outright defeat.

Tuesday brought a night of high drama as the vote count seesawed through hours of counting ballots and Twitter came alive with running commentary. At different times, Cochran and McDaniel were above the 50 percent threshold, only to slip back below it because of a third-party candidate who drew just 1.6 percent of the vote.

The runoff could be even dirtier than the primary, given the high stakes. The lines have been clearly drawn. The Cochran forces will portray McDaniel as the candidate of out-of-state interests, and one whose positions and past statements could make him vulnerable in the fall against former congressman Travis Childers, who won the state’s Democratic Senate primary on Tuesday.

“We are going to push hard for Thad because he is the candidate looking out for Mississippi’s interests, while McDaniel is beholden to the out-of-state forces funding his campaign,” Henry Barbour said in an e-mail early Wednesday. “Mississippi needs to have a senator we can count on and trust — and not a trial lawyer who says he’s for tort reform but argues in court it’s unconstitutional so he can make a bunch of money.”

McDaniel’s forces, in turn, will do what they have been doing, which is to paint Cochran as out of touch with the new Republican Party, insufficiently conservative and not up to the fight of taking on President Obama and the Democrats in the battles ahead.

The Club for Growth, one of the most prominent of the outside groups backing McDaniel, called on Cochran on Wednesday morning to quit the race. In a statement, President Chris Chocola said: “Senator Cochran has served honorably, but the rationale for his candidacy ended yesterday. He said he didn’t want to run again, but everyone asked him to. Well, a plurality of Mississippi Republican voters just proved that they don’t want him to.”

Runoff elections are treacherous for incumbents, a fact that puts Cochran in considerable peril. Tuesday was a second wake-up call for the longtime senator, a brush with political extinction. He may have three more weeks to show what he has learned from the experience.

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