21st Amendment repealed Prohibition. 18th Amendment authorized it.
Potato, drunk potahto. 
If I understand correctly, SCOTUS didn’t *change *the outcome at all, it just *upheld *the already-existing outcome. How is that undemocratic?
From SCOTUS’ point of view, the already-existing outcome was a recount ordered by the Florida Supreme Court.
I get most of the amendment numbers mixed up but these should be easy:
21 – Can Drink. … 18 – Not Old Enough.
That tells you more about the Republicans of today than Obamacare. They can’t truly be as opposed to it as they indicate, since it’s basically made from their own health care proposals from the 1990s.
It’s the result of a recent party strategy change to absolute obstruction rather than a sign that it was rammed down the public’s throat. The majority of people either supported it or didn’t feel that it went far enough, so it can hardly qualify as one of the most unpopular legislative decisions of all time.
Obama would get 0% Republican support for a national acknowledgement that puppies and kittens are cute.
Yeah, if people think that a democratically elected president who campaigned on reforming health care and then got his legislative package through congress is the most undemocratic thing to happen in the US, every American woman born before 1920, ever black American born before 1968, and every American Indian ever would like to have a word with you.
This is what most Democrats tend to forget. The recount process had already played out, as provided for under Florida state law, with the result being Bush won. Democrats convinced a judge to order an additional recount, not provided for under election laws. This is what the Supreme Court stopped. There are practical reasons for this: you don’t want elections to degenerate into a never-ending morass of recounts and legal chicanery in trying to get enough of the right votes counted so your guy wins.
Back to the OP, I’ll second the TARP program. It was severely unpopular, altho there were very practical reasons for it.
Democrats probably forget that because it isn’t true. There was no “recount process that had already played out.” Gore requested a manual recount as provided by state law. It was the only recount that began, much less got completed. He could have requested a machine recount but did not.
I’d hardly call that “severely unpopular.” Rather, it looks to me like different ways of asking the question led to different results. Are you looking at different poll numbers?
Obviously, voter suppression laws.
US entry in to WW1 has to up there, even with the Lusitania and Zimmermann Telegram, there was never a majority opinion in favor of it.
Which, however, are undeniably popular with some segments of the public.
My understanding is that the Vietnam war was quite popular for the majority of the war.
Actually undemocratic and unpopular are the same thing. Unrepublican and unpopular are not the same thing.
As an alternative way of quantifying the question, which were the most popular initiatives that failed because they did not attract a super-majority or through filibuster?
Libya
True, Jefferson did send ships to the Med without getting Congressional approval first. But a couple months later he did get it.
If you want an example of a President waging war without Congressional approval, try the 1983 invasion of Grenada.
Martial Law?
He absolutely can – anytime, anywhere. The War Powers Resolution gives him carte blanche to invade anybody he wants for 60 days, and then, if Congress gets up on its hind legs and insists that he withdraw all the troops, he has 30 more days to do that. But AFAIK, Congress has never done that since the resolution was passed.
For reference, it took less than three weeks for Baghdad to fall after Bush invaded in 2003, and Iraq was allegedly the most dangerous country in the world. So 60 days is forever.
ETA: it’s true that he can’t declare war all by himself, but we haven’t declared war on anybody since WWII, so that’s meaningless.