(Bloomberg) -- The mention of abortion in political television advertisements has surged since a draft US Supreme Court opinion on Roe v. Wade was made public.

In US House races, 22% of pro-Democratic ads and 24.5% of pro-Republican ads that ran since the May 2 leak mentioned abortion, according to a report from the Wesleyan Media Project, which tracks campaign spending. Previously, 6.2% of Democratic and 13.5% of Republican ads mentioned the issue.

“Clearly, the country’s attention has turned to abortion rights, and we’re seeing the shift in political advertising as well,” Travis Ridout, co-director of the Wesleyan Media Project, said in a report released on Thursday. “Abortion is an issue that not only separates Democrats and Republicans, but the issue could matter in primary races as well.”

The increase in abortion mentions also has shown up in Democratic Senate and gubernatorial ads, and in Republican gubernatorial spots, the report showed.

Politico first reported the leaked draft opinion that potentially could overturn the landmark 1973 ruling that legalized abortion.

TV ad spending for the crucial midterm elections is climbing as candidates bombard voters weighing inflation and abortion before deciding which party will control Congress and dozens of state offices. 

The sheer number of ads this year is up as well. The Wesleyan Media Project, a collaboration of academics from Wesleyan University, Bowdoin College and Washington State University, has tracked more than 1 million ad airings in this election cycle for federal and gubernatorial races, a 32% increase over the same period for 2018. 

Estimated total spending is approaching $500 million this year, compared to $315 million in 2018, with more ads from senatorial and gubernatorial races. Pro-Republican spots, aired for primary campaigns and early general election campaigning, “substantially outnumber” the pro-Democrats ads, according to the report.

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