Is Mitt Romney planning a $5 trillion tax cut? Will money saved by ending the wars in Afghanistan and Iraq help “rebuild America,” as President Obama claims?

Many voters rely on the news media and independent fact-checkers to determine when a politician is telling the truth or twisting it. Instead, couldn’t we pass laws preventing politicians from lying while running for office? Unfortunately, as election law expert Richard L. Hasen points out in a recent paper, candidates may have a constitutional right to fib.

“It is depressing to think that the Constitution contains within it a right to lie in political campaigns,” Hasen writes in “A Constitutional Right to Lie in Campaigns and Elections?,” a paper for the University of California at Irvine’s law school. “However, the state may no longer have the power to ban or punish malicious false campaign speech, whether made by candidates or others.”

According to Hasen, this year’s Supreme Court case U.S. v. Alvarez, which struck down the Stolen Valor Act, protecting a man who falsely claimed that he had received the Medal of Honor, shields candidates who tell tall tales. After Alvarez, obviously incorrect statements that disenfranchise voters could still be prohibited — for example, “Republicans vote on Tuesday, Democrats vote on Wednesday.” But mendacious politicians, such as “a person who used to be a judge referring to himself as a ‘Judge’ in an ad” or lying about an endorsement, could still monkey with the truth.

What’s the solution? Hasen finds an extrajudicial remedy in what Justice Anthony M. Kennedy calls “counterspeech” — opponents of a lying candidate can “credibly call that candidate a liar.”

That is, if they can speak loudly enough.

“With candidates’ pants increasingly on fire, and with the wooden noses of campaign consultants growing ever longer, the question is whether counterspeech . . . will be enough to give voters the tools they need to make intelligent choices,” Hasen writes.

Justin Moyer, Outlook editorial aide