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Nearly halfway through President Trump's first 100 days in office, political sleuths are still trying to pin down exactly how Hillary Clinton lost the presidential election last year. A new study by the Wesleyan Media Project might offer some insight by looking at what Clinton and Trump focused on in their TV advertisements, Vox reports — and if Democrats want to win in 2020, they might do well to pay attention.

Clinton spent just 25 percent of her advertising going after Trump on policy, the study found. Trump, on the other hand, spent over 70 percent of his TV ads discussing policy. Clinton spent about 90 percent of her attack ads slamming Trump's personality as opposed to focusing on why his policies were worse than hers. Her decision was unusual: Every political candidate since at least 2000 dedicated more than 40 percent of his advertising to policy attacks.

In fact, talking about Trump's personality likely backfired for Clinton: "Evidence suggests that … personally-focused, trait-based negative messages (especially those that are uncivil) tend to be seen as less fair, less informative, and less important than more substantive, policy-based messaging," the researchers wrote. "Trump, on the other hand, provided explicit policy-based contrasts, highlighting his strengths and Clinton’s weaknesses, a strategy that research suggests voters find helpful in decision-making."

Read their full results here, and Vox's analysis of the findings here.