Democrats "vote Blue no matter who". The Republicans, on the other hand, will not vote for anyone who isn't sufficiently Fascist, irrational or evil - "RINOs".

The DNC rationally doesn't have to offer anything to get D votes, so they instead concentrate on "moderate" Republican voters. And RNC politicos also concentrate on the right wing of their party, so as not to be RINOs.

Thus each election, both parties move to the right. Now the US is at the point where any R victory might mean the end of free and fair elections forever.

It's too late now, but things would have been a lot better if the D voters have pushed back a generation or more ago, and hard.