2020 longshot Seth Moulton on Friday took a swipe at former Vice President Joe Biden after he reversed his decades-long stance on federal funding for abortions -- by challenging him to also admit he was "wrong" in supporting the Iraq War.

“Bravo to @JoeBiden for doing the right thing and reversing his longstanding support for the Hyde Amendment. It takes courage to admit when you’re wrong, especially when those decisions affect millions of people. Now do the Iraq War,” Rep. Moulton, D-Mass., tweeted Friday.

Moulton’s tweet comes after Biden, who is currently the front-runner in the crowded 2020 Democratic primary race, reversed his position on the 40-year-old Hyde Amendment, which restricts the use of federal funds to subsidize abortions.

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Biden has maintained his stance in favor of the amendment for decades, despite facing backlash from members of his party. But as the issue of abortion has taken center stage in early 2020 primary discussions, Biden changed his mind.

On Thursday, Biden said he “can no longer support an amendment that makes” a woman’s right to abortion “dependent on someone’s ZIP code.”

“I make no apologies for my last position and I make no apologies for what I’m about to say,” Biden said at an event in Atlanta on Thursday. “I can’t justify leaving millions of women without access to the care they need and the ability to exercise their constitutionally protected right.”

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Biden’s announcement came as he promised a new universal coverage health care plan that would “provide the full range of health services that women need,” with the “continued expansion of Medicaid and a public option of a Medicare plan.”

Moulton's tweet, though, recalled Biden's Senate vote in favor of the Iraq War. Moulton, a Marine Corps veteran, led one of the first infantry platoons to Baghdad and served four tours of duty during the war.

Back in 2005, Biden did say he made a mistake in supporting the invasion of Iraq.

“It was a mistake,” Biden said on NBC’s Meet the Press in 2005. “It was a mistake to assume the president would use the authority we gave him properly.”

Biden's late son Beau Biden, who died of brain cancer in 2015, also served in Iraq.

The Biden campaign did not immediately respond to Fox News' request for comment.

Biden and Moulton are just two of the two-dozen Democrats vying for the nomination to compete against President Trump in the 2020 general election.

Moulton, who only entered the race in April, is among the lowest-polling candidates in the field thus far, and in some polls does not even register with 1 percent.

Fox News' Vandana Rambaran contributed to this report.