Democratic presidential front-runner Hillary Clinton slips 5, 7, and 8 points with millennial voters in matchups against Donald Trump, Marco Rubio and Ted Cruz when hit with just one attack ad , according to a Republican research firm that uses the same kind of randomized control groups that clinical drug trials do.  

Younger voters were key to Barack Obama’s victories, of course, and Adam Schaeffer, chief science officer of Evolving Strategies, said Clinton appears to be surprisingly vulnerable with that demographic, especially given that the ad used in the test “was pretty lame and muddled in my opinion, but was the best thing out there.”  

We already know that younger voters favor Clinton’s Democratic primary rival Sen. Bernard Sanders by large margins – and that millennials don’t reliably turn out to vote.  

But Schaeffer argues that the findings should concern the Clinton campaign because she will need those voters to win. The attack ad used in the test, which was sponsored by the Stop Hillary PAC, focuses on Clinton’s handling of the deadly attack on the U.S. consulate in Benghazi — an issue that isn’t particularly potent with younger voters, who generally aren’t as concerned about terrorism as older voters.  

The control group saw a Coke commercial “with cute little animals” — puffins and polar bears — cracking open a soda.  

The 2012 GOP nominee, Mitt Romney, pulled in around 37.5 percent of voters aged 18 to 34, which means Cruz is at parity with Romney, Trump is behind where Romney was with those voters, and Rubio outperforms. Even with the impact of the ad taken into account, Trump barely exceeds Cruz’s baseline with younger voters, and falls well short of Rubio’s.  

Trump’s numbers change the least, too, which is not terribly surprising since both the billionaire businessman and the criticism of him are already quite well known.  

But that’s true of Clinton, too, which means she should be more impervious to an attack that this one test suggests she might be.  

In similar tests in 2012, Obama attacks on Romney hurt him only slightly, by a couple of points. But Obama’s numbers didn’t move at all in response to a Romney attack ad, just as you’d expect given how well known Obama and the criticism of him already were at that point.  

“It’s hard to move an incumbent, and we thought Clinton would test much more like an incumbent,’’ given how long she’s been on the national stage, Schaeffer said.  

One caveat in all political forecasting this year is that while Cruz and Rubio would by all indications run fairly similarly — with the same campaign structure, anyway — it’s more difficult to predict how Trump might perform as the nominee since he appeals to people who may not have been voting at all, and may or may not turn out in November.  

The firm conducted a randomized-controlled trial with over 1,000 18-to-34-year-old respondents they randomly assigned to the “treatment group” that was shown the attack ad or the placebo-control group that saw the non-political commercial. Then they compared the vote outcome in the treatment group to the control group to determine the impact from the ads.

Contact Henneberger at melindahenneberger@rollcall.com
and follow her on Twitter at @melindadc.

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