Tuesday’s primaries show there’s no doubt the Democratic Party is lurching to the left. The last time Florida Democrats won the state’s governorship was in 1994. With GOP Gov. Rick Scott leaving office to run for U.S. Senate, Democratic Party leaders were determined to nominate a candidate who could appeal to centrists. They recruited former U.S. Rep. Gwen Graham, the daughter of a popular former governor and U.S. senator, who had won support from business in the past. But in a major upset, Graham lost the gubernatorial primary to Tallahassee Mayor Andrew Gillum, who had the endorsement of Bernie Sanders...