Paul Ryan is done with herding cats: He’s stepping down as House speaker come January, and leaving Congress altogether after 20 years.

It’s a big loss to the Republican Party and to the country as a whole.

Ryan’s colleagues all but made him take the job back in 2015 after their infighting forced Speaker John Boehner to quit.

And he proceeded to prove he was the right pick, keeping the GOP factions united to produce last year’s landmark tax reform, slashing rates for businesses and individuals to end the slow growth of the Obama years.

As well as restoring sorely needed defense funding in this year’s budget compromise.

That he’s the first speaker in decades to leave on his own terms is a telling sign of the deep divisions that define modern US politics.

But he had the wisdom to realize it was time for him to move on so his teenagers can know him as more than a “weekend dad,” and to let someone else lead the House.

“We all know that I did not seek this job, I took it reluctantly,” Ryan said, “but I have given this job everything that I have.”

We hope he’ll be back to give his all for the nation in some other impossible job.