Apparently, as HBO's John Oliver was poking fun at Pennsylvania's charter school system, Pennsylvania Sen. Anthony Hardy Williams wasn't laughing.

On Wednesday, Williams (D., Phila.) sent the Last Week Tonight host a "Dear John" letter, questioning an assertion on his Sunday show that Pennsylvania's "charter schools are terrible."

"I really do enjoy your wit and informative style," Williams wrote, "but you went too far with your segment on Pennsylvania's charter schools."

On his program Sunday, Oliver used Pennsylvania laws and Philadelphia schools as examples of why he believes charter schools are something of gamble when it comes to education.

"Charter schools unite both sides of the aisle more quickly than when a wedding DJ throws on 'Hey Ya,' " Oliver said to kick off his piece, further noting that the first charters emerged 25 years ago as a way to explore new approaches to education.

Earlier this year, Pennsylvania Auditor General Eugene DePasquale said the state has "the worst charter school law in the United States."

Oliver agreed.

"That is not good," Oliver said, before launching into a side rant. "It is not like having the worst 'something' is new for Pennsylvania. Remember, this is the state that has the worst football fans, the worst bell, and the worst regional delicacy. Yes. If I wanted Cheez Whiz on my steak sandwich, I'd eat at Kiddie Cafeteria, the restaurant run by 6-year-olds."

Williams, after taking umbrage with Oliver's attacks on the state, said Pennsylvania delivers quality education "to children who can't afford to move to a better district!"

"By the way, you also forgot to mention in your 'charter schools are terrible' commentary that this is also the state where traditional public schools have some major challenges," Williams wrote.

News stories about the school district in the past few years, Williams wrote, have ranged from "teachers and principals caught cheating on standardized testing to
embezzlement — unfortunate commentary on any institution which receives public funding, charter or traditional."

Williams also pointed to a 2015 Stanford University study that found "urban charter schools on average achieve significantly greater student success in both math and reading.

"I'm just saying," Williams wrote.

Williams, who lost to Jim Kenney in the 2015 mayoral race,  calls himself "an original architect of Pennsylvania's landmark charter school legislation," and founded his own in Southwest Philadelphia that nearly closed in 2003 because of academic and management problems, according to a 2011 Inquirer story

In the letter's conclusion, Williams called Oliver "my mann (that's a Philly reference)," and added that because it was a "Dear John" letter he could no longer watch Oliver's program.

"Though I'm probably lying to myself," Williams said.

Mayor Kenney also weighed in on Oliver's segment, though his beef with the piece was different from Williams':