Folks are always saying that they want politicians to work together, but that's not how they vote. Look at primaries. If a politician dares to support a proposal from the other side of the aisle, or dares to state that his/her objective is to "work across the aisle", they are nearly always vilified by their opponents in the next primary. Worse, the voters typically vote against such a "work together" politician and vote for the "true believer" candidate instead. It happens time and time again. This is the fundamental reason so many politicians fear primary challenges. It's interesting that one of the consequences of this is that often the more moderate candidate loses the primary; and therefore in the general election, the voters only have the option of voting for a far right or far left candidate. So the Congress gets more and more polarized leading to less and less "working across the aisle" since the moderates are stopped at the primary.