Who’s the frontrunner to win the 2020 Democratic presidential nomination? We’ve made some arguments before for Sen. Kamala Harris, focusing on social media buzz and other less-used metrics. But here’s another: A tipster who receives all RNC press releases and “one-on-one” emails tells us that a survey of emails sent between January 1, 2019 and today shows more focus on Harris than on Sen. Bernie Sanders– a typically popular punching-bag for the GOP. A ton of these RNC emails naturally focus on things like bashing the Green New Deal or undercutting former Trump lawyer/”rat” Michael Cohen. The RNC also sends press releases out when its Chairwoman, Ronna Romney McDaniel, appears on TV (party chair TV appearances usually get about 30 viewers, so the committees like to bump up the numbers in any way they can, including with “In Case You Missed It” (ICYMI) emails with YouTube links to appearances). But…