Defamation* is is illegal but the legal fees and time needed to sue in court are so excessive that in politics, there simply isn't time to let the justice system provide adequate protection. In effect, I can essentially say anything I want about my opponents and leave them to clean up the mess. They are forced to waste their money and time to set the record straight, are derailed from their message, and may lose an election not because they were bad candidates but because they were the covered with the most muck.
Right now, the FTC "truth in advertising" law requires that all advertising be truthful, fair and substantiated but this is limited to protecting consumers, i.e., advertisements for something that you buy or pay for. So politicians can use the same "telecommunications and electricity" governed by the FTC to say just about anything that want, under the legal protection of the First Amendment and the practical protection of our legal red tape.
Now imagine if we changed our laws slightly. First, broaden the definition of "consumer" in federal truth-in-advertising laws to anyone paying attention to the advertisement. Second, amend our defamation laws to include a simple reprimand that anyone issuing falsifiable statements as facts has to retract and correct their statements in the exact same way in which their original claims were made.
Knowing that you have to stand back up on that podium and retract your claim about 80 communists in the Senate, or that you have to pay another $6.4 billion to correct all your malicious claims in prime-time TV might just be the kick-in-the-pants needed to make our leaders, and their wealthy supporters, think twice before opening their mouths. Maybe elections would become a little more about the best candidate winning versus the last one standing.
The protection of free speech is a cornerstone to our society, but we have to weigh this against (1) the rampant abuses that are being made now that anyone with enough money can have a microphone with nationwide reach, and (2) the ethical requirement that people who are or aspire to be our leaders should do so truthfully and without deception. It would be interesting to see lawyers argue before the Supreme Court that the First Amendment protects the rights of people in positions of enormous public influence to lie to us.
If you agree, please write your Congressional and Senate representatives and tell them to Reprimand the liars and bring facts back to the public discourse.
*Cribbed from wikipedia: Defamation—also called calumny, vilification, traducement, slander (for transitory statements), and libel (for written, broadcast, or otherwise published words)—is the communication of a statement that makes a claim, expressly stated or implied to be factual, that may give an individual, business, product, group, government, or nation a negative image.