In the 2008 Democratic primary season, Hillary Clinton got hit repeatedly for her vote in favor of the 2002 Iraq War resolution. Her chief opponent, Illinois Sen. Barack Obama, had been a vocal opponent of military action in Iraq, which proved an important element in his upset win.

A dozen years later, another prominent senator from that era who backed the Iraq War resolution, Joe Biden, is the front-runner for the Democratic nomination. With the passage of time, the war has been denounced by much of the general public as a mistake. Yet, it’s still an open question whether Biden, who went on to serve eight years as Obama’s vice president, will be hurt by that vote nearly 17 years ago.