Republican Sen. Rand Paul attacked Republican Sen.-elect Mitt Romney on Wednesday for virtue signaling. Paul was responding to the 2012 GOP presidential candidate’s Washington Post op-ed, in which Romney attacked President Donald Trump just days before being sworn in as Utah’s junior senator.

“To a great degree, a presidency shapes the public character of the nation. A president should unite us and inspire us to follow ‘our better angels,'” Romney wrote in the piece published Tuesday, adding, “And it is in this province where the incumbent’s shortfall has been most glaring.” (RELATED: Mitt Romney Writes Anti-Trump Op-Ed, Questions Trump’s Character)

In response to the criticism, Paul came out swinging against Romney, comparing him to Republicans who attacked Reagan when it was popular. “Like other Big Government Republicans who never liked Reagan, Mitt Romney wants to signal how virtuous he is in comparison to the President,” Paul tweeted, “Well, I’m most concerned and pleased with the actual conservative reform agenda @realDonaldTrump has achieved.”

Like other Big Government Republicans who never liked Reagan, Mitt Romney wants to signal how virtuous he is in comparison to the President. Well, I’m most concerned and pleased with the actual conservative reform agenda @realDonaldTrump has achieved.

https://t.co/vNvp2ZwyK7 — Senator Rand Paul (@RandPaul) January 2, 2019

Romney’s op-ed drew the ire of Republicans across the board. Republican Party Chairwoman Ronna McDaniel, who is Mitt Romney’s niece, called the op-ed “disappointing and unproductive” on Twitter.

McDaniel tweeted, “POTUS is attacked and obstructed by the MSM media and Democrats 24/7. For an incoming Republican freshman senator to attack @realdonaldtrump as their first act feeds into what the Democrats and media want and is disappointing and unproductive.”

POTUS is attacked and obstructed by the MSM media and Democrats 24/7. For an incoming Republican freshman senator to attack @realdonaldtrump as their first act feeds into what the Democrats and media want and is disappointing and unproductive. https://t.co/ArhI7Bi7bo — Ronna McDaniel (@GOPChairwoman) January 2, 2019

Trump endorsed Romney for his Senate race and his presidential run in 2012. Romney sought a cabinet position in the early Trump administration. In response to the critical article, Trump tweeted, “Here we go with Mitt Romney, but so fast! Question will be, is he a Flake? I hope not. Would much prefer that Mitt focus on Border Security and so many other things where he can be helpful. I won big, and he didn’t. He should be happy for all Republicans. Be a TEAM player & WIN!”