So far, a Democratic super PAC called "Duty and Country" has spent well over $1 million assisting the candidacy of Republican Don Blankenship for U.S. Senate in West Virginia.

Blankenship, the former Massey Energy CEO who is running in the Republican primary, went to prison for mine safety violations that contributed to a 2010 mining accident that killed 29 people. He is now promoting a conspiracy theory about Senate Majority Leader Mitch McConnell's supposed involvement in trafficking cocaine.

Blankenship is viewed as unelectable ( which may or may not be true), and although he currently polls in third place ahead of next Tuesday's primary, Republicans are terrified at the possibility that he could win their party's nomination anyway.

The conventional wisdom has been that Democrats are pouring money into the Republican primary because they see Blankenship as their best chance of holding on to Democratic Sen. Joe Manchin's Senate seat. But a new survey from Morning Consult suggests that Blankenship might actually be their only chance.

When Manchin won his first Senate election in 2010, Democrats controlled the entire state government and all statewide offices. And he was very popular personally.

Because he had been appointed, Manchin faced another statewide election in 2012. Republicans felt they'd have a chance against him, given the state's gradual shift toward them. But Manchin's immense personal popularity as a former governor prevented the race from even becoming close. It helped that Manchin was willing to buck the national Democratic Party at times.

Then West Virginia's party realignment came like a lightning bolt in 2014. Whereas some Southern states took as many as five decades to fully realign from Democratic to Republican, the Mountain State went from one-party Democratic to solid Republican almost overnight. Three years later, Manchin is one of just two statewide elected Democratic officials left, and the only one with any real power.

Democrats are still counting on Manchin's immense personal popularity to help them cling to a Senate seat they will probably need if they want to have a Senate majority this fall. But a lot has happened since Manchin last faced the voters.

Is he still Mr. Popular? The new Morning Consult poll says, not really.

Manchin's new approve/disapprove spread of 41 to 46 percent isn't that bad from an objective point of view. He's only five points underwater. But that's down from 16 points net positive iat the beginning of 2018. Manchin has suffered a 21-point slide in just four months.

And for someone whose party label is as toxic as an abandoned slurry pond, and who is depending on his personal popularity to win in a state where voters now comfortably vote against Democrats by default, even a break-even approval rating probably isn't going to do it for Joe Manchin against any decent Republican opponent.

Unless, that is, Republicans nominate the worst Senate candidate in America. And that's why Democrats are spending so much to tinker in the Republican primary, praying themselves to sleep and hoping for a Blankenship win.