'I won big and he didn't!' Trump fires back at Mitt Romney and tells him to 'be helpful'

President Donald Trump on Wednesday hit back at incoming Sen. Mitt Romney (R-UT) for his scathing Washington Post op-ed in which he slammed the president's moral character.

"Here we go with Mitt Romney, but so fast!" Trump wrote on Twitter. "Question will be, is he a Flake? I hope not."

After making an unflattering comparison between Romney and outgoing Sen. Jeff Flake (R-AZ), Trump told Romney to stop attacking him and "be helpful" to his presidency.

"Would much prefer that Mitt focus on Border Security and so many other things where he can be helpful," Trump wrote. "I won big, and he didn’t. He should be happy for all Republicans. Be a TEAM player & WIN!"

In his op-ed, which dropped on Tuesday night, Romney said the Trump White House underwent a "deep descent" in December and vowed to speak out against the president when necessary.

"His conduct over the past two years, particularly his actions this month, is evidence that the president has not risen to the mantle of the office," Romney wrote. "It is not that all of the president’s policies have been misguided… But policies and appointments are only a part of a presidency."