That was surely due to the fact that his party had been devastated on Election Day 2010 due to the successful muscling-through of liberal desiderata—from a nearly $1 trillion stimulus to a United Auto Workers Union bailout (in the form of the auto bailout) to ObamaCare.

No. The challenge didn’t come because Obama is black. A primary challenger would have had to overcome black block-voting and, if Obama lost, the black vote likely wouldn’t turn out to support the person who challenged (and defeated) Obama.

The liberal/progressive movement is of course the ideological core of the Democratic Party.

There is a conservative movement and a Republican Party, but it often seems as if the two scarcely occupy the same space.