Sen. Elizabeth Warren is a front-runner in the 2020 Democratic primary race and, according to polling aggregation site RealClearPolitics, she and former vice president Joe Biden are virtually tied in national polls.

As her campaign has gained traction, a story that Warren often tells on the campaign trail — about getting fired from her first teaching job for being pregnant — has been put in the spotlight. The story has resonated, at least in part, because pregnancy discrimination is still common today.