[sudosysgen]

Because the presidency is vastly more powerful than what you think. Obama could have pulled an FDR, or a Trump, and shifted the party very hard, but didn't. It's quite simple: you go to your opponent, you tell him that if he doesn't follow the whip you will use your vast reach to get him primaried, threaten to modify the rules of the DNC, hell, drum up support for a general strike. Threaten to slash the military budget, threaten to cancel a defence program, or to stop shale oil subsidies, play politics. But for some reason, from FDR onwards, no one plays politics except to concede towards the right. Literally no one in power. The platform of the Democratic Party has become "Let's be Republican-lite in order to win those elusive moderate independent" that for some reason seem to shift more and more towards the right for every single election cycle for the last 40 years, almost as if they were illusory or weren't as ideologically unmovable as asserted.

And it's total bullshit that the Democratic Party wouldn't consider a public option. The Republican Party was considering a public option.