There are, of course, many exceptions, but the overall trend is clear. Democrats are hitting their Republican opponents over past legal transgressions, shady business deals and even speeding tickets. Republicans are hammering Democrats over “Obamacare,” Nancy Pelosi and the economy.

A recent study by the Wesleyan Media Project actually quantifies this. They looked at 900,000 airing of political ads this year and concluded: “Democrats are using personal attacks at much higher rates than Republicans and a much higher rate than Democrats in 2008.”