Political attack ads are ramping up as Election Day approaches, and half the ads in U.S. Senate races across the country over the past month have been purely negative. That’s the finding of a report released this week by the Wesleyan University Media Project.

Michael Franz is with the Wesleyan Media Project. He said advertising in U.S. Senate races has also been more negative than in the 2010 and 2014 midterm elections. He said this is probably because control of the Senate will depend on the outcome of just a few races in places like Tennessee and Nevada.

“These are the razor tight, razor thin margin seats where the entire control of the Senate and of course what happens with judicial nominations and so on will be the deciding factor on who controls that in the next two years. So I think that’s why we are seeing so much negativity there,” Franz said.

He said it appears most of the ads are focused on older voters.

“Older Americans are still much tied to their television sets, live TV. And so to that extent to see TV ads in the cycle is not too surprising. However, it is surprising to nonetheless see the volume increase as much as it has, especially given the rise of social media. So it could be that this cycle is a do everything cycle because the stakes are so high,” Franz said.

He said for Democrats healthcare continued to dominate advertising in the month of September, with one fifth their ads specifically defending Obamacare. He said that is a marked departure from the two previous midterm elections.

This report comes from the New England News Collaborative, eight public media companies including Rhode Island Public Radio, coming together to tell stories of a changing region.