The content of political ads in the U.S. is very, very loosely regulated. Unlike every other sort of advertisement, political candidates can (at least in most circumstances) make blatantly false or misleading statements with blanket immunity in the name of free speech. And, as anyone who's watched a television come election time, this quickly turns things into a mudslinging race to the bottom.
Some have clamored for government regulation to curb false or misleading statements-- but it's not at all clear that we could trust (say) the FCC to be a good gatekeeper for political discourse, nor whether trying to outlaw false statements wouldn't mire political campaigning in layers and layers of frivolous and non-frivolous lawsuits to be sorted out laboriously and expensively by the legal system. Simply put, the legal system doesn't move fast enough to mediate political debate, nor do we want the side with the best lawyers to win.
So, besides government regulation, what can be done to help our political discourse suck less?
I'd like to suggest something that could be put into play by any candidate, at any time, with little expense and no legal reforms necessary. Essentially, if one found oneself in a dirty race where ones opponent was making blatantly false or misleading statements, instead of just slugging back, they could ask a respected, neutral third party to fact-check their advertisements before airing, and inform their viewers about it. I envision a statement like this at the end of a political ad:
"There's a loophole where political candidates can legally say almost anything to get elected, true or false. We thought you deserved better, so we had the official Congressional Research Service review this ad and they found it non-misleading and factually correct. Can candidate X say the same?"
As with so many other things, the devil's in the details- what famously neutral research organization would resonate well enough with voters (and agree to participate) so the other side couldn't just bring in their own obscure partisan "factcheckers"? Could you use this against last-week-of-the-election smear campaigns? Where do you draw the boundary on 'misleading'? How do you fit this into a small part of a thirty-second ad- and so forth. But I think such things could be worked out and that this strategy would likely improve political discourse- and since taking the moral high ground first is so powerful, it might even help win some elections.