Conservatives fall into a trap when they start complaining about unfairness. Yet that’s what many have been doing in the days since New Jersey Gov. Chris Christie’s “Bridgegate” scandal broke and former Virginia Gov. Bob McDonnell and his wife were indicted for accepting illegal gifts.

If conservatives complain the media isn’t being tough enough on President Barack Obama, they shouldn’t complain when the media is tough on other political figures — even if they happen to be Republicans. The ultimate goal isn’t some subjective sense of “fairness.” It’s a strong, independent Fourth Estate that holds all politicians accountable.

The Media Research Center’s Brent Bozell pointed out the disparity in how news outlets have covered Christie’s scandal, compared to Obama’s scandals, including the IRS’s targeting of conservative groups.

“The two controversies aren’t even close in importance,” Bozell said. “One is a lane closure on a highway. It’s obnoxious. It’s petty. It’s beneath the governor’s office. It’s a scandal. It should be covered — no question about it. The other one is using the most feared arm of government as an intimidation, even a persecution arm against the citizenry of America.”

He’s right, but his outrage is misplaced. Instead of defending Christie and all but dismissing Bridgegate, he should have called for the media to turn the same appropriate focus on the IRS scandal.

We’re hearing some of the same complaints now about McDonnell, who was charged on Tuesday.

“Authorities allege that for nearly two years, the McDonnells repeatedly asked executive Jonnie R. Williams Sr. for loans and gifts of money, clothes, golf fees and equipment, trips, and private plane rides,” the Washington Post reported. “The gifts and loans totaled at least $165,000. In exchange, authorities allege, the McDonnells worked in concert to lend the prestige of the governor’s office to Williams’s struggling company, Star Scientific, a former small cigarette manufacturer that now sells dietary supplements.”

McDonnell claims the prosecution is political; his supporters say the media is subjecting him to closer scrutiny than any Democrat regularly receives.

In neither scenario should conservatives play either the fairness or the victim cards.

First, it’s not out of the realm of possibility that a New Jersey elected official turns out to be a scrapper? That New Jersey politics involves some payback from time to time. Sure there’s no indication as yet that Christie was directly involved in ordering the bridge closure, but if he did, that’s something we should all know about before getting too far along in the presidential primary process.

As for McDonnell, corruption knows no political boundaries. There are good and bad politicians in both parties, and the proper response of conservatives isn’t to rush so quickly to his defense — it’s to let the criminal justice system do its job now.

If there’s a double standard — and it does seem that there is — then to fix it, we need a media habitually critical toward both parties. That’s the proper role of the Fourth Estate.

“Fairness” is a vague and unattainable standard. Let’s shoot instead for “equally tough.”