He's been unpopular for years. You'll forgive me if I don't have much expectation of him losing.
I'm aware. I don't think there's that great a chance of the Democrats knocking McConnell off, but I also don't think it's impossible.
Of course, there's also the other option for the Democratic Party, which is to expand the courts (killing the legislative filibuster if necessary). Then put four or six more Justices on the Supreme Court, and also a good number on the circuit and district courts, given how many cases stop at those.
(What I'd actually advise them to do is change the filibuster rule to make it so that any vote must have the support of not only half of the Senate, but Senators representing half of the population of the states. The Democrats have had a majority in the Senate in the latter sense continually since at least 1985. Now granted such a rule change, even if only internal to the Senate, might be unconstitutional, since the US Constitution is explicit that each Senator has one vote. But it'd be worth exploring.)
EDIT: As for DailyKos' summary, sure, but, like I said, that could backfire if the Supreme Court makes a decision that sparks
Dred Scott levels of outrage. That would enable the Democrats to run specifically on ignoring that decision, just as the Republicans did in 1860.