The Democratic Party will likely split into a new centrist party and a new far-Left Progressive party. It’s like the Whigs falling apart in the 1850’s.
And that, my FRiend, should be our biggest nightmare. Likely that "centrist" aspect of the democrats would merge with the RINOs to form the RinoCrats. On the basis of the numbers, they'd rule for a long time.
Like I said, start an islamic party and a green party and democrats are toast.
We have libertarians to contend with, but that too could be switched into a Sanders-libertarian party.