Fox News senior judicial analyst Andrew NapolitanoAndrew Peter NapolitanoFox News analyst: Republicans are protesting their own impeachment inquiry rules Fox News's Bret Baier calls Trump's attacks on media 'a problem' Trump urges GOP to fight for him MORE defended Rep. Adam SchiffAdam Bennett SchiffHouse panel advances resolution outlining impeachment inquiry Overnight Defense: Pentagon shares images of al-Baghdadi raid | Bolton called for impeachment inquiry deposition | Russia ambassador pick pressed on surveillance flight treaty House calls for Bolton deposition as part of impeachment inquiry MORE’s (D-Calif.) handling of the impeachment inquiry amid fierce criticism from GOP lawmakers, with Napolitano stating the rules Republicans are complaining about were written when the party controlled Congress in 2015.

“Congressman Schiff is, in my opinion, following the rules of the House of Representatives. You generate the information in secret. You decide which you want to make public. You can’t use anything against the president that hasn’t been challenged and aired in public," Napolitano told "Fox & Friends."

“So his [President TrumpDonald John TrumpTrump congratulates Washington Nationals on World Series win Trump hints that dog injured in al-Baghdadi raid will visit White House Vindman says White House lawyer moved Ukraine call to classified server: report MORE's] lawyers, whoever they are going to be, ultimately will be seated at a table at the House Judiciary Committee challenging that evidence," he continued. "When that challenge is over, the House Judiciary Committee votes, and then the House of Representatives votes.”

Schiff serves as chairman of the House Intelligence Committee and is helping lead the impeachment inquiry. 

“The Republicans have asked for a vote, so they’re getting this vote about the procedure of the inquiry going forward," noted co-host Steve Doocy. "But also want it to be fair. There is nothing fair about this. Congress has got some screwy rules.”

“Congress does," Napolitano agreed. "The rules were written in 2015 when Republicans controlled Congress. And now they are stuck with those rules.”

“They come back to haunt the Republicans," replied Doocy.

“Yes, it has come back to haunt the Republicans," said Napolitano. "One of the more interesting phrases that I heard the other day is an impeachable offense is whatever the House says it is. Because at that point, it’s political.”

House Democrats will hold their first floor vote on impeachment Thursday, shifting the process from being behind closed doors to being public and broadcast on television.

If impeached in the Democratic-controlled House, 20 Republicans in the Senate would have to vote with Democrats to get the 67 votes required for Trump to be removed from office.