Mississippi Sen. Thad Cochran's stunning runoff victory over conservative state Sen. Chris McDaniel on Tuesday night broke almost every rule of politics.

After trailing the lesser known McDaniel in the June 3 primary, Cochran, in three weeks time, managed to: a) grow the electorate in his favor by, among other things, recruiting African Americans to his cause b) run successfully on a message of keeping his seniority in Washington and c) win despite, quite clearly, being the less naturally skilled candidate on the stump.

Doing one of those things in three weeks time would be astounding. Doing all three is like watching someone pitch a political perfect game; you'll not see a victory like this one any time soon.

So, how did he do it? I talked to several people involved in either the Cochran campaign or other outside groups that helped the incumbent in the wake of his victory. Here's what they told me.

* He convinced black voters to be for him. According to the Fix's Philip Bump, runoff turnout in the 24 counties with a black population of 50 percent or more was up almost 40 percent from the primary. In all other counties, turnout was up just 16 percent.  That is an absolutely stunning stat -- and tells much of the story of the runoff.  Cochran's ability to convince a strongly Democratic constituency to be for him -- despite the fact that every Democratic consultant believed McDaniel gave the party a better chance to win the seat in the fall -- is simply remarkable.

* He found lots more votes in his base. Every time I asked Cochran allies what their path to victory was in the runoff, they told me that lots and lots of Cochran voters didn't cast ballots on June 3 because they didn't really think the incumbent was in trouble. I rolled my eyes. Not in trouble? After millions of dollars in TV ads on both sides and national media coverage of the race everywhere?  Well, they were right. In Hinds County, Cochran's base, he got 10,928 votes on June 3.  On Tuesday night, he got 17,927 (with 99 percent of precincts in the county reporting). For you non-math majors out there, that's 7,000 more votes in three weeks time.  McDaniel, on the other hand, got 5,621 votes in Hinds on June 3 and 6,962 votes on June 24 -- an increase of just over 1,000. Considering that Cochran's margin statewide will be around 6,500 votes, you might say that was the difference.

* He let DC deliver the money.  Between the primary and the runoff, $1 million in PAC money was raised for Cochran, including more than $800,000 in a single night thanks to a big assist from Mississippi Sen. Roger Wicker and Senate Minority Leader Mitch McConnell.  Raising that sort of money for Cochran in DC allowed the incumbent to spend his time meeting and greeting voters in the state.

* He fought the "it's over" narrative. In the immediate wake of the primary, lots (and lots) of people in the political world wrote the race off. (I was among them. My theory was simple: If voters weren't for a 36-year incumbent on June 3, what would change their minds three weeks later?) To their credit, the Cochran campaign as well as the National Republican Senatorial Committee fought like hell against that narrative. The Chamber of Commerce and the National Association of Realtors, who had been for Cochran in the primary, immediately signaled they would keep spending in the runoff. McConnell and the rest of Cochran's peers didn't let off the gas. (See the money point above.) Perception matters in politics and no one in Cochran's world let him be perceived as a dead man walking on June 4.

* He bet on incumbency.  Look at Cochran's message on TV in the closing days of the race. It's a Republican message circa 2004: I have tons of seniority in the Senate and that means good things for the state.  Vote me out and you can kiss all of that goodbye. (Hell, he brought Arizona Sen. John McCain in to campaign for him in the final days of the contest!)  There is absolutely no evidence -- before this victory -- that a longtime incumbent running on being, well, a longtime incumbent could win in the modern day Republican party.  And especially not in a runoff! It did in this case. Now, whether that's because Mississippi is a state that depends on significant federal largesse or because the runoff electorate was filled with lots of nontraditional Republicans (and plenty of not-at-all Republicans) remains to be seen. But, regardless of why it worked, it worked.

All in all, an absolutely amazing race. One that will be studied by political science classes (and me!) for years to come -- and rightly so.

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