The last time Thad Cochran failed to win an electoral majority was 1978, when he won a three-way race with 45% of the vote to win his first term in the U.S. Senate. On Tuesday, his quest to win a nomination for a seventh term was stymied by State Sen. Chris McDaniel, who has fervently attacked Mr. Cochran as a profligate pork-barrel appropriator who is soft on immigration and endorses ObamaCare. The race became a battleground for the national schism in the Republican Party, with Tea Party-aligned Super PACs, including the Club for Growth and the Senate Conservatives Fund, spending over $5 million for Mr. McDaniel. Various groups, including the business-aligned Chamber for Commerce, have spent around $3 million on Mr. Cochran, in addition to the $3 million spent by the Senator’s own campaign.
But with 99% of precincts reporting, the race appears to be going to a runoff on June 24. Mr. McDaniel narrowly leads with 49.5% of the vote; Mr. Cochran trails with 48.9%. A third candidate, Thomas Carey, is largely unknown but appears to have garnered enough votes (1.5%) to prevent either Mr. McDaniel or Mr. Cochran from earning a majority. With turnout likely to be even more lackluster in a runoff, the enthusiasm of Mr. McDaniel’s activist base gives him an advantage; in any case, we can expect national groups to again spend heavily to unseat Mr. Cochran. With well-funded campaigns to defeat other incumbents perceived as insufficiently conservative fizzling, including those against Sen. Mitch McConnell (Kentucky) and Rep. Mike Simpson (Idaho-02), this is their final chance. The winner will be favored to hold the seat in deep-red Mississippi against Democratic ex-Rep. Travis Childers, though Mr. Childers would have a better chance against Mr. McDaniel.