Oh where have you gone, Republican “oppo” (opposition) researchers?

As dozens of Democratic presidential hopefuls begin to test the waters with their party’s primary voters, many of them are finding those waters filled with piranhas.

Amy Klobuchar is a senator from the North Star State who dipped her toe in and CHOMP. Stories about her brutalizing staffers were promptly released and did significant damage.

No more Ms. Minnesota Nice Guy for Klobuchar. She’s now the wicked witch of Minneapolis. She recently bragged to a crowd of college students that she had carried Michelle Bachmann’s congressional district and then had to prod them, “That’s when you guys are supposed to cheer.”

Reporter John McCormack likened it to hopeless Jeb Bush’s infamous “please clap” moment.

A similar thing has happened to many fellow Democrats. Joe Biden is now “Creepy Uncle Joe” for his wandering hands. Elizabeth Warren is now not just someone who played up family lore about Native American ancestry, she arguably lied about it to the Texas State Bar.

And the hits keep coming. But not, curiously, from Republicans.

The GOP used to be good at oppo research. Feared, even. Operatives for the national party and countless other state affiliates and related groups would pour through the records of Democrats on the rise and gather evidence. It was all kinds of good, deep dive stuff.

When Democrats announced they were running for office, the GOP oppo squad would release the results of this research to the Drudge Report, local papers, or television affiliates and then send it viral. And Democrats would get blown up.

Lately, though, Republicans have been slacking. How did Ed Gillespie’s campaign not know about all the Virginia blackface stuff among top Democrats, for instance?

The thing that kicked off the controversy was a photo in a yearbook. A yearbook! This is oppo 101 stuff. Everybody looks at yearbooks. You just go to a public library and crack a few books. And yet, the GOP flunked it.

Or take the case of Beto O’Rourke. He once wrote stories under the pen name Psychedelic Warlord. One of the stories chronicled a murder spree, starting with a child killing fantasy where the narrator ran down two happy children who were innocently crossing the street.

Dear God!

O’Rourke recently lost a Senate race to Ted Cruz, narrowly. And the only question we’re left with is, how? Cruz should have been just hammering O’Rourke every single day of that campaign for his child killing fantasy.

Did Cruz not have the goods? If not, why not? Why didn’t the National Republican Senatorial Committee? How can a candidate for Senate who rises to national liberal celebrity not face scrutiny for his repugnant scribblings?

There are many reasons for this dereliction, no doubt. But I want to take one of them and squash it like a bug. People may disdain oppo research because we should be about “the issues” and only the issues.

That’s not just high-minded, it’s dangerously wrong. Competence is an issue. And character is an issue that’s likely to affect job performance. Republicans who hold their fire over some bizarre misapprehension that Democrats will extend them the same courtesy, allow me introduce you to Brett Kavanaugh, who was recently accused of running a gang rape ring.