Trump trashes 'overrated' conservative pundit George Will for calling for his defeat
Commentator George Will, Donald Trump -- screenshots

Never one to let a slight go by without firing back, presumptive GOP presidential candidate Donald Trump lashed out at conservative stalwart George Will for calling for his defeat after the pundit announced he was leaving the Republican Party specifically because of the candidate.

Using his favorite messaging medium, Twitter, Trump wrote: "George Will, one of the most overrated political pundits (who lost his way long ago), has left the Republican Party. He's made many bad calls"

Friday, Will gave a speech to the Federalist Society only to announce that he was leaving the GOP, saying, “This is not my party."

Will also left with a parting shot, saying Republicans need to "make sure he [Trump] loses" in the fall, and to grit their teeth and set their sights on reclaiming the White House in four years -- presumably from former Secretary of State Hillary Clinton.

Trump returned to New York early Sunday morning after a whirlwind tour of Scotland to promote his golf courses and, incidentally, his presidential campaign.

As of Sunday morning, Will had not responded to Trump on Twitter, with the columnist's last post urging Republicans to not donate to the New York businessman.

Trump and Will's tweets tweet below: