NYC mayor Bill de Blasio was the subject of mockery on Wednesday after attempting to slam his Democratic rival former Vice President Joe Biden over a key issue on abortion.

Biden ruffled feathers among progressives after he said he supports the Hyde Amendment, which outlaws federally funded abortions with exceptions to rape, incest, and life of the mother. Last month, however, Biden appeared committed to abolishing the amendment, a position that nearly all the prominent 2020 candidates have taken.

On Wednesday, Biden's camp clarified the former VP's position on the issue has not changed, and he "misheard" the question when asked if he supports the Hyde Amendment.

However, before Biden was able to correct the record, many seized on Biden's seeming backflip on a key issue.

New York City Mayor -- and 2020 Democrat hopeful -- Bill de Blasio was one of those who tried to score some points off Biden, however things did not work out quite as he would have liked.

"The Hyde Amendment only hurts low income women, especially women of color. If you don’t support repeal, you shouldn’t be the Democratic nominee," de Blasio tweeted.

He then followed up by writing: "And when it comes to supporting American women on issues like repealing the Hyde Amendment, @JoeBiden is Dr. Jekyll."

Many on Twitter, however, fact-checked the NYC mayor, telling him that Dr. Jekyll was "the good one" from the classic Robert Louis Stevenson novel.

The literary confused capped off a rough few days for de Blasio, who was the subject of President Trump's ire on Twitter Monday morning.

While taking aim at London Mayor Sadiq Khan, Trump described the British politician as the "twin" of de Blasio “except shorter.”

The New York mayor, a Trump critic himself, is 6'5. Khan is 5'6.