WASHINGTON – Having attacked some of his critics as "Do Nothing Democrats," President Donald Trump reserved a harsher term Wednesday for "Never Trumper Republicans" who continue to opposed him amid an impeachment inquiry.

"Human scum."

"The Never Trumper Republicans, though on respirators with not many left, are in certain ways worse and more dangerous for our Country than the Do Nothing Democrats," Trump tweeted Thursday. "Watch out for them, they are human scum!"

Trump has ratcheted up his criticism of Republicans in recent weeks, as some GOP lawmakers question his decisions to withdraw U.S. forces from Syria, pressure Ukrainian officials to weigh into U.S. politics and select a Florida property he owns to host the next G-7 summit of world leaders. Trump later reversed himself on the Florida resort and has described his July 25 phone call with Ukraine as "perfect."

During a mid-day tweet storm, Trump identified one of his Never Trumper critics as Bill Taylor, the diplomat who told House impeachment investigators Wednesday he was "alarmed" by the linking of aid to investigations of Trump's Democratic rival Joe Biden.

Other Republicans who oppose Trump proudly claimed the mantle the president bestowed on them.

Responding to Trump on social media, Peter Wehner – who worked for three Republican presidential administrations – said: "What those of us who are 'human scum' with an exclamation point particularly appreciate is how you've more than validated our concerns about you-psychologically, morally/ethically and in terms of temperament/judgment."

He added: "You turned out to be at least as bad as we warned you'd be."