Mississippi Sen. Thad Cochran overcame the odds Tuesday to win a contentious Republican runoff and is now favored to win a seventh term.  

Two weeks after the stunning loss by House Majority Leader Eric Cantor, R-Va., state Sen. Chris McDaniel hoped to become the latest challenger to unseat a sitting member of Congress in a GOP primary.  

But, after finishing 1,400 votes behind McDaniel in the June 3 primary, Cochran was able to expand the electorate  — a feat, pro-Cochran Republican insiders cautioned in the days leading up to the runoff, that hadn’t been achieved in Mississippi statewide elections in recent decades. Cochran led 51 percent to 49 percent when the Associated Press called the race with 98 percent of precincts reporting. He is now strongly favored against former Rep. Travis Childers, a Democrat, whose potential for success was largely based on a McDaniel victory.  

This Republican-leaning state hasn’t elected a Democrat to the Senate since 1982. President Barack Obama, who struggled across the South in both of his elections, took just 44 percent of the vote in Mississippi in 2012.  

The Cochran campaign kicked off the runoff with a plan to target voters who hadn’t participated in either the Republican or Democratic primaries. Three weeks ago, Cochran underperformed and even lost counties where his campaign expected to succeed.  

He also received major financial boosts from the U.S. Chamber of Commerce and the National Republican Senatorial Committee, which spent $175,000 in independent expenditures and helped raise more than $800,000 on Cochran’s behalf.  

To enlarge the runoff electorate — which increased by more than 30,000 votes from the primary — Cochran and his allies expanded their outreach to blacks and Democrats who had not voted in the Democratic primary and were therefore eligible to vote on Tuesday. Mississippi does not register by party, so primaries and runoffs are open.  

That appeared to work, as turnout surged in heavily black Hinds County by more than 7,000 votes and Cochran won it with 73 percent.  

The campaign also altered its message to put even more emphasis on highlighting specific examples — county-by-county — where Cochran’s Senate influence directly benefited Mississippians. That paid off as well, as he won coastal Jackson County — which he lost in the primary before highlighting the shipbuilding jobs he’s supported through federal appropriations — and increased his vote total there by more than 1,200.  

McDaniel supporters were more vocal and energized than Cochran’s, and the state legislator’s backers included many longtime Cochran voters who were looking for a change — not necessarily because of a distaste for Cochran, but rather in an effort to send someone who could help change Washington .  

The ability of Cochran to change the makeup of the electorate ensured his 36th year in the Senate wouldn’t be his last.