Stacey Abrams? Kamala Harris? Elizabeth Warren? Nobody knows for sure whom Joe Biden will choose as a running mate if – as is almost certain – he wins the Democratic nomination, but we do know it will be a woman.

“I’ll pick a woman to be vice-president,” Biden promised during Sunday’s presidential debate with Bernie Sanders. “There are a number of women qualified to be president tomorrow.” While none of those eminently qualified women will be president any time soon, one lucky lady may have the privilege of playing second fiddle to a gaffe-prone white guy. To cement his position as intersectional male feminist of the year, Biden also promised to appoint an African American woman to the supreme court.

Don’t get me wrong, I am pleased Biden will pick a female running mate. Apart from anything else, there is normally a vice-presidential debate, and I would love to see Mike Pence, who refuses to eat dinner alone with a woman other than his wife, get eviscerated by a member of the “second sex”. However, Biden’s reveal also made my eyes roll; it felt a lot like pandering. Representation is important – but not as important as policy. I am with Sanders, who did not commit to a female running mate, but said: “For me, it’s not just nominating a woman; it’s making sure we have a progressive woman.”

Sadly, pandering gestures tend to be more politically effective than principled stances. Sanders says what he believes, not what will make an expedient soundbite. His uncompromising integrity is his biggest strength, but it is also his biggest flaw. It is the reason he has built a grassroots movement of devoted followers and it is the reason he will lose to Biden.

• Arwa Mahdawi is a Guardian columnist