David Axelrod, a Democratic strategist and onetime chief strategist for former President Barack Obama, is warning that a third-party candidate could derail President Joe Biden’s reelection campaign. In a Tweet on Friday, Axelrod warned that Cornel West, the academic favored for the Green Party’s presidential nomination, could tip the scales in favor of the Republican nominee. “In 2016, the Green Party played an outsized role in tipping the election to Donald Trump,” Axelrod said, alluding to Jill Stein, the Green Party candidate who analysts contend siphoned enough votes off Hillary Clinton to shift the outcome in key states. “Now, with Cornel West as their likely nominee, they could easily do it again. Risky business,” Axelrod wrote.