Left entryists have fought to take over the Democratic Party. 2018 is their test.

Three notes about Tuesday’s election:

1. This is a test for entryism.

Wherever one comes down on Democratic entryism – the only way forward, necessary but insufficient, a suboptimal political investment, a waste of time, or counterproductive – it seems clear to me that tomorrow has to be regarded as a great empirical test. Nearly three years ago, Bernie S…