Trump campaign takes aim at Joe Biden's possible 2020 run: 'The Left just doesn’t get it'

The next presidential election may be years away, but the Trump team is already targeting one possible 2020 Democratic challenger.

SEE ALSO: Joe Biden is creating a political action committee

In a campaign email sent to supporters on Monday, Trump headquarters responded to swirling rumors that former Vice President Joe Biden is mulling a bid to challenge President Trump for the White House.

"American voters rejected Hillary Clinton's and Barack Obama's disastrous policies last November, but now Joe Biden is preparing to challenge President Trump in 2020," the campaign wrote in an email that also requested campaign donations.

Click through some of the top names who might run against Trump in 2020:

The Trump campaign called Biden an "extreme liberal" who will "spend every waking minute over the next four years trying to tear down OUR President."

"Joe Biden won't be the only Democrat to try to stop all of Donald Trump's progress, and with the fake news media committed now more than ever to spreading lies about the President, we need to be ready," the campaign continued in the email.

Biden admitted after Clinton's 2016 election loss that he regretted not running for president after eight years as vice president.

"I had planned on running for president and although it would have been a very difficult primary, I think I could have won," Biden said. "I don't know, maybe not. But I thought I could have won."

"But do I regret not being president? Yes. I was the best qualified," Biden added.

Biden's name has recently picked up steam as a top prospect for Democrats in 2020. While speaking at the SALT Conference in Las Vegas, the former vice president said "he may very well run" for in the upcoming presidential election.

"I never thought [Hillary Clinton] was the correct candidate," he added. "I thought I was the correct candidate."

The former vice president added even more fuel to the fire after launching a political action committee this week — a telltale sign that he might be contemplating something further.

Attacking potential 2020 opponents isn't anything new for President Trump. While speaking at the National Rifle Association (NRA) Leadership Forum in April he mockingly said "It may be Pocahontas" in 2020, "And she is not big for the NRA," referring to Sen. Elizabeth Warren.

Warren told MSNBC host Rachel Maddow in April she's "not running for president in 2020."