In 1936, Gallup polled people, asking “Would you vote for a woman for president, if she were qualified in every other respect?” This question, and other examples of surveys targeting women in politics, is documented by Vicky Randall in her book “Women and Politics: An International Perspective.”

Unfortunately, the latest example of such behavior came 80 years later from an unlikely source: Sen. Bernie Sanders.

At a rally at Temple University in Philadelphia, according to Politico, Sen. Sanders told the crowd, “We have won, we have won seven out of eight of the recent primaries and caucuses. And she has been saying lately that she thinks that I am, quote unquote, not qualified to be president.

“Well let me, let me just say in response to Secretary Clinton: I don’t believe that she is qualified if she is — if she is, through her super PAC, taking tens of millions of dollars in special interest funds,” he said. “I don’t think you are qualified if you get $15 million from Wall Street through your super PAC.”

Sanders added, “I don’t think you are qualified if you have voted for the disastrous war in Iraq. I don’t think you are qualified if you’ve supported virtually every disastrous trade agreement, which has cost us millions of decent-paying jobs. I don’t think you are qualified if you supported the Panama free trade agreement, something I very strongly opposed and which, as all of you know, has allowed corporations and wealthy people all over the world to avoid paying their taxes to their countries.”

Clinton’s campaign and Philadelphia supporters pointed out that their candidate never said Sanders was unqualified, and demanded he take back his words, according to Hanna Trudo and Nick Gass with Politico.

In Sanders’ defense, Clinton did dodge questions about whether Sanders was qualified, after he gave a poor interview with the New York Daily News, even as she endorsed him over Republican rivals. But she did avoid calling him unqualified, a term Sanders couldn’t resist using, as so many have done in the past.

Robert Borosage wrote a column defending Sanders: “But the kerfuffle was all nonsense. Sanders doesn’t think Clinton is ‘unqualified,’ as he quickly acknowledged. He has repeatedly paid respect to her experience and qualifications. And the rhetorical misstatement frankly wasn’t all that harsh.”

Actually, Sanders did directly say Clinton was unqualified. And he said it repeatedly in his statements in front of a large crowd. It was unnecessary, as it clearly detracted from some otherwise good points Sanders was making about Clinton’s record. And it played into the old attacks that female candidates have had to repeatedly face over the years.

The old Gallup poll question about “would you vote for a woman for president if she was qualified” is frequently given to voters, with results that hyped in the press — even if only five percent say no, the press will claim it will cost her in a close race. Nobody asks “would you vote for a white male if he was qualified?”

Borosage cites the 2008 election as a nastier one about qualifications, but both Obama and Clinton refrained from calling each other unqualified, as they made subtle jabs at each other. Sanders is a longtime politician and a seasoned pro at campaigning. He knows what he’s doing.

If Sanders loses the primaries, historians are likely to cite this moment as a critical mistake, a gaffe that blunted his momentum after beating Clinton in several states.