The six women vying for the Democratic Party’s presidential nomination in 2020 start the race with more than 1 in 10 Americans saying they’re less suited to politics, merely because of their gender.

A new report from Georgetown University’s Center on Education and the Workforce contends the candidates — who include four senators, Kirsten Gillibrand of New York, Kamala Harris of California, Amy Klobuchar of Minnesota and Elizabeth Warren of Massachusetts, along with Hawaii Rep. Tulsi Gabbard and author Marianne Williamson — face a deficit that’s “still too substantial to ignore.”

Authors Anthony P. Carnevale, Nicole Smith and Kathryn Peltier Campbell base it on the General Social Survey, an annual study begun in 1972 and conducted by the National Opinion Research Center at the University of Chicago, which found last year that 13 percent of Americans are still biased against women in politics, down from a peak of almost 50 percent in 1975.

But a deeper look at the campaigns of actual women candidates, based on studies across decades, calls their pessimism into question. Robert Darcy and Sarah Slavin Schramm of George Washington University wrote in a 1977 article that a congressional candidate’s gender had “little or no effect on election outcomes,” for example.

In 1985, John Zipp and Eric Plutzer of Washington University in St. Louis found the same in their study of 1982 Senate and gubernatorial races. In 1994, Barbara Burrell of Northern Illinois University wrote in her book, “A Woman’s Place Is in the House: Campaigning for Congress in the Feminist Era,” that women are as successful at winning elections as men.