Presidents-elect often tries to connect with ordinary Americans following elections, but Trump is bring his own signature style to the effort.
In a tweet on Tuesday, the president-elect suggested those who desecrate the flag should be jailed or stripped of their citizenship.
The four are among a growing number seeking to lead the Democratic Party in a time of diminished power.
It is unclear which of the president-elect’s proposals would have kept the student out of the United States.
The president-elect suggested that those who burn the U.S. flag should have their citizenship revoked.
The Supreme Court in 1990 ruled that flag-burning was protected free speech under the Constitution. Trump’s revival of the long-settled legal issue follows a flag-burning recently at a Massachusetts college.
The senator from Vermont warns the president-elect to steer clear of a tactic embraced by “nondemocratic countries.”