I think a 'absolutist' positions on the left in the USA were thrown out of the window seventy years ago, and what remained was decreased ever more over the years, as the Right moved Right, the Left moved center, and the centrists hunted the moving target. I can't recognise any true leftist objective in what the current Democrat leadership advances, not to speak of a markedly leftist agenda.

Moreover, this is not just a question of representing voters. If you want to represent a bad opinion, you'll execute bad policies, and it will hit you back. And since the Republican machine won't fall dead, it will hit you back damn hard.

If you want four years of stagnation, followed by a real Republican landslide (and a Preisdent who is not just vile but has an IQ over 100, say Jeb Bush), then vote for the tepid DLC Democrats.

Dear Americans on the Left, if you want to achieve what the Republicans have, changing public opinion in their direction and creating a voting majority on their side, then quit arguing about electability and start arguing for your positions. Here is an example that it can work, from Italy:

Regional elections were held in 14 provinces in April this year. People voted for party lists for the regional assemblies, and separately voted for a regional president. In Puglia province,  (the 'heel' of the Italian 'boot'), a certain Nichi Vendola won the presidency, against these odds:

1. Vendola was selected in a US-style primaries vote by the base, rather than chosen by party leaders as the one seen most electable,
 
2. he is a communist (and attacked for it),
 
3. he is openly gay (and rather strongly atacked for it),
 
4. he won in a Southern province (where people are more conservative),
 
5. he won with 6% more than the last centre-left candidate,
 
6. he won by more than the supporting L'Unione coalition on list votes (0.1% more - that must have come from the right!),
 
7. he won while the L'Unione vote included 3.28% vote for the Christian Democrat UDEUR and its centrist allies!