Conservative critics of the left-leaning media are increasingly turning their fire on their own, accusing center-right outlets of playing along with Democrats and their campaign to portray hardened liberals as open-minded "progressives."

Rumblings among conservatives, which started in the 2016 presidential campaign when socialist Sen. Bernie Sanders was dubbed a "progressive," spilled out this month when Texas Rep. Lamar Smith slammed right-leaning media for using the term.

Smith, the co-chairman of the Congressional Media Fairness Caucus, wrote a two-page letter to conservative media outlets demanding they replace "progressive" and "mainstream" for "liberal."

While he pulled his punches by suggesting the practice was "inadvertently engaged in by conservative journalists," Smith said in his letter provided to Secrets that using the word "progressive" is inaccurate, misleading and confusing to the public.

"To use the word ‘progressive' to describe liberals causes confusion and misleads the public. Why would Republicans deliberately let Democrats define the terms of engagement," Smith asked.

He then turned to the term "mainstream media," writing, "The national media welcome the description ‘mainstream' because they want to give the impression, which is false, that they represent most Americans. We should not give them that satisfaction but call them what they are, the ‘liberal' national media."

The founder of the Media Research Center, famous partly for its bumper stickers that read "I Don't Believe the Liberal Media," said Smith has nailed it.

"Anyone who knows me knows I despise the phrase 'mainstream media.' There's not a thing about them that is 'mainstream.' They aren't even liberals. They're now hardened leftists," said L. Brent Bozell, whose group polices liberal media, especially TV.

And he was equally tough on conservative outlets for their adoption of positive-sounding terms that give liberal Democrats cover.

"Rep. Smith is correct. Our side is too intellectually lazy at times. We must think before we speak — or write," Bozell said.

Smith has another pet peeve about the word "progressive," saying it refers to former Republican President Teddy Roosevelt's post-presidential Progressive Party. According to Smith, "it was a popular political movement because it broke up some of the large corporate cartels of the time. However, today's progressives favor government intrusion into almost every aspect of our lives."

Paul Bedard, the Washington Examiner's "Washington Secrets" columnist, can be contacted at pbedard@washingtonexaminer.com