Why Are Political Ads Allowed To Run Misinformation?

Midterm elections are underway, and with them come political ads that aren't always true. Why is that allowed?

Lies in political ads are common. There are entire news segments dedicated to investigating what's true and what's not. But are candidates allowed to be dishonest in ads? 

David Oxenford is a broadcast and digital media lawyer. 

"Can candidates lie in political ads? That really depends on how you look at it," said Oxenford.