People forget because Biden made his one term promise in an extremely dishonest and slimy way. He never actually explicitly promised to be a one term president. Instead, his campaign organized a large series of representatives to go out and imply that he would be a one term president. He got a bunch of Democratic big wigs to go around telling people that he would only run for one term. His campaign organized all of this messaging, but he himself never made the promise with his own lips.

It wasn't just a mistake, it was a deliberate deception. He lied to the American people. He just crafted his lie carefully to provide plausible deniability later. Sure, there were tons of people, on his orders, saying that he would be a one term president. But he never actually promised to drop out after one term!

He's a slime ball.