It’s still early in the 2020 campaign cycle, so political predictions are risky. Nonetheless, it appears that the race for the Democratic presidential nomination has already become a two-person contest. Elizabeth Warren has replaced Bernie Sanders as the most formidable challenger to front-runner Joe Biden according to the most recent YouGov, SurveyUSA, and NBC/WSJ polls. All show Warren gaining on Biden and Sanders falling back to third place. Assuming these polls are accurate, the rest of the Democratic candidates are stuck in single digits. This is very good news for President Trump, who will have little difficulty beating Biden or...