The Dems' threshold for the tax cuts used to be $0.00
and it was unanimous: every single dem voted against the Bush tax cuts, in other words, the unanimous Democratic party position was to keep tax rates at Clinton levels for everyone making over $0.00 per year. I'd be willing to bet that no one at DU, not a single person, not even jiacinto, argued that any Democrat should vote for those tax cuts.
Obama at the very beginning of his first campaign set his level at $250,000. He won the primaries, and two general elections, and his position remained the same the whole time, so I have no problem accepting it at this point.
But I disagree with the idea that that is some magical figure and that anything less than that, including letting ALL the tax cuts expire, is out of the question. The $250,000 didn't come from God, it came from a politician (who won a number of elections convincingly.)