Seen a lot of political ads on TV lately? Advertising expert Bob Kolt says there's a simple explanation, last-minute ads work.
"You really want to motivate people to move out and go to the polls, sometimes people who are undecided might not make a decision until the last moment when they're voting, so that advertising can have an effect," the Michigan State University professor said.
He says some people are still undecided because, in an election in which both major presidential candidates have 60 percent disapproval ratings, people are voting by the "least objectionable politician" theory.
"They don't like either one of the politicians, and they're going to vote for the person who offends them less," Kolt said.
Hillary Clinton's campaign says it will spend $100,000 on a TV ad campaign in Michigan. Her campaign said in a statement, "Michigan is an important state and Hillary Clinton has been campaigning aggressively here in order to win on Election Day."
Donald Trump's campaign is also buying up TV ads.
"The national campaign just added a 25 million dollar buy to several states including Michigan, so we're very excited, we're ramping up," Scott Hagerstrom, the Michigan State Director for Donald Trump for President, said.
Kolt says both moves mean the campaigns are treating Michigan like a critical piece in the election.
"It's good that Michigan is on the radar because it could go either way," Kolt said.