John Curtis is a real piece of garbage.

That’s probably your takeaway if you live in the 3rd Congressional District and have gone out to your mailbox recently to snag the stacks of mailers attacking the Provo mayor and Republican congressional candidate.

He’s a tax-raising, budget-busting, Hillary Clinton-loving former Democrat and he’s not to be trusted to be a conservative in Congress.

A new mailer from the PAC supporting Tanner Ainge quotes Curtis as calling himself “a flaming liberal,” leaving out the next line: “I‘m joking.”

It’s the type of distortions and negative campaigning that voters always say they don’t want to see. So why is there so much of it?

Because it works.

“We like to say we don’t like negative ads. We love to say that,” said Dave Hansen, a long-time Republican campaign operative. “You can’t find 10 people in the entire state who say, ‘I love negative ads.’ But, at the same time, they have an impact.”

It’s even more predictable that the GOP primary race would get nasty for three reasons. First, Curtis started the primary with a decent cushion over Chris Herrod and Tanner Ainge, meaning the other two candidates have to hack away at him to bring Curtis back to their level.

Leah Hogsten | The Salt Lake Tribune Tanner Ainge, John Curtis, and Chris Herrod. The three Republican primary candidates in the special 3rd Congressional District race.

Second, Curtis does have a record and that record does, indeed, include supporting some tax hikes as Provo mayor and running for state Senate as a Democrat in 2000 — easy targets for attack ads.

And third, there is not a lot of daylight between the three candidates when it comes to the issues. They’re all essentially running on the age-old Republican mission of getting the federal government out of your life, giving control back to the states and balancing the budget.

The only way for Herrod and Ainge to get back into the race was going negative.

And they’ve done it with the help of big money — about $750,000 so far — spent by out-of-state political action committees thriving in the post-Citizens United world, where groups can pour endless money into campaigns.

Studies have shown that, when the attacks are run by third-party groups, voters tend to not blame the candidates for the negativity.

But Ainge and Herrod may be venturing into some dangerous territory.

Marty Carpenter ran Gov. Gary Herbert’s re-election bid, and said Utahns are sensitive to the outside money and Washington D.C.-backed groups and it gives the target of the ads, Curtis in this case, an opportunity to play the victim.

Hansen said when he ran Sen. Orrin Hatch’s 2012 campaign, the conservative group Freedomworks was hammering the senator with negative out-of-state advertising. But instead of responding with attacks on Hatch’s opponent, the Hatch campaign went negative against Freedomworks, an easier target, criticizing the out-of-state interlopers trying to tell Utah voters how to vote.

In a debate Monday, both Herrod and Ainge gave feeble defenses of the ads, saying they can’t tell the PACs what to do. They’re right, to a point. Campaigns are not allowed to coordinate with third-party groups.

But what if that outside group is essentially your family? That’s what’s going on with Ainge. The Conservative Utah PAC is based in Washington, D.C., and headquartered out of a law firm about three quarters of a mile from the White House. The PAC has dumped about $238,000 into the race, pretty much exclusively on media and direct mail. But the money has come from Ainge’s family — $250,000 from his mom, Michelle.

You think if Ainge publicly asked his mom to stop the ads, she wouldn’t?

Herrod, at least, can claim a little more separation. Club for Growth and the affiliated PAC, National Horizon, have spent a combined $300,000 so far on campaign ads, including one called “Halloween” with cartoon pumpkins and bats mocking Curtis and Ainge for pretending to be conservative.

But he still has to answer: What does Club For Growth gain from getting him elected? And how can he not be part of the Washington establishment if it’s the Washington establishment that got him into office?