House Republican campaign chief says remark criticizing retiring GOP lawmaker 'a mistake'

At left, Rep. Steve Stivers, an Ohio Republican and chairman of the National Republican Congressional Committee, and at right, Rep. Ryan Costello, a Pennsylvania Republican

(CNN)The chairman of the National Republican Congressional Committee retreated Monday from his remark that a retiring colleague lacked the "intestinal fortitude" to run for reelection.

In an interview last week with CNN, NRCC Chairman Steve Stivers rejected the idea that Rep. Ryan Costello, a Pennsylvania Republican, had decided to retire in part due to the "political landscape," as Costello claimed. Instead, Stivers said Costello lacked the guts to face recent changes to his state's congressional map, which made his district more competitive.
"He didn't cite the political landscape when he had the old map that was R+2," Stivers said. "I think it was a lack of intestinal fortitude on his part, and that's unfortunate. He should have stuck in there and fought, I think he would have won that district."
But Stivers is now backing off of that harsh assessment, saying it was "a mistake."
    "It was a mistake of me to say," Stivers said in a statement Monday. "Ryan is a friend and we're sad to see him leave. I'm sure he made the right decision for his family and his district, and I respect it."
    Stivers had started to come under fire for his remark, with the Democratic Congressional Campaign Committee highlighting it in a press release Sunday.
    "Wow....so much for Ronald Reagan's Eleventh Commandment," the release said — a reference to Reagan's famous code, "Thou shalt not speak ill of another Republican."
    Indeed, it is unusual that the House Republican leading his party's re-election efforts would issue such a stark criticism of a colleague, much less during the heat of a midterm election year.
    But Stivers is contending with a flood of Republican retirements, further complicating his efforts to maintain the GOP's grip on the House, with the political odds seemingly stacked against them. Forty-one House Republicans so far will not return next year, compared to 19 House Democrats.