Former President Barack Obama has the power to bless and curse congressional candidates with his support. Take his endorsements of 81 candidates from around the country.

One word from Obama inspires the nostalgia needed to help a California or a New York candidate clinch their race. One word from Obama could also sink an incumbent in a red state, running for their lives away from Trump-loving electorates.

Obama knows this, and that is undoubtedly why Obama didn’t endorse any of the most vulnerable Senate candidates. He gives Rep. Jacky Rosen the nod as she tries to knock off Sen. Dean Heller, a Republican, in Nevada. At the same time, he steers clear of the likes of Democratic Sens. Joe Donnelly of Indiana and Joe Manchin of West Virginia. They’re probably grateful.

It’s not that Obama is unpopular. He enjoys a favorability rating upward of 60 percent since leaving the White House. It’s that Obama is especially unpopular in certain places.

Imagine the nightmare Manchin would have to endure if Obama endorsed him. The electorate in that state loves the current president and hates the past one because of his war on coal. Manchin already faces an uphill battle. An endorsement would be an anchor around the neck of a senator barely keeping his head above the waves in shark-infested waters.

Or imagine the headache an endorsement would create for Donnelly. Obama carried Indiana during his first election, so it might not be the end of the world for the candidate. But it would create fodder for attack. The sad reality is that while Donnelly and Obama often got along all right, an endorsement from the former president just isn’t worth the risk.

His help would do more to hurt the neediest in his old party, and so Obama, in a moment of self-awareness, has played it safe.

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