<p>But promoting socialism, sky-high taxes, and open borders is probably not going to help them trounce the GOP in November. The activist base of the Democratic party is lurching left fast enough that everyone should pay attention. Activists matter because their turnout in low-turnout primaries and caucuses almost propelled leftist Bernie Sanders to victory over Hillary Clinton in 2016. Last month, Alexandria Ocasio-Cortez unseated New York congressman Joe Crowley, the No. 4 ranking House Democrat in a low-turnout primary. She benefited from organizing support from the Democratic Socialists of America. Leftists have also upset establishment Democrats in statewide primaries for governor in Colorado and Maryland.</p>