Despite the fact that Republican policies (and actual Republicans) are deeply unpopular with the American people, we nevertheless get "deals" that are very Republican-policy heavy. It shouldn't be that way and there are lots of little things that add up to get this result (a pretty good rundown in this piece). The short of it is that Republicans are much better at the game of politics than Democrats. If that doesn't change then neither will our political results.
Unfortunately it really can't change in large part because people who support Democrats are [generally] offended by the way that Republicans play the game, and so if Dems were to do the same, a fair number of people, who are already hard to get to the polls, would be even less inclined to participate, making it easier for Republicans to win (even when they lose).
In order to unwind the problems in our politics, Democrats would have to act (a lot) more like Republicans, but people hate the way Republicans act (particularly supporters of Democrats). It's a catch-22.
Note: If you want to know if you are one of those people there is a pretty easy test: how do you feel about Nancy Pelosi? If you like her, you support stronger Democrats, if you don't then, like it or not, you support the crap situation we are in.