The right and left wings of the Republican and Democratic Parties do not appear to have symmetrical tactics. The right, usually in the House but often in the Senate, refuses to compromise even when that refusal will generate a worse short-term result from their perspective. For instance, the right in the House has refused to vote for federal spending bills even if they were written by the Republican leadership. In 2012, the most conservative caucus refused to vote for a bill that would have limited tax hikes to those earning over a million dollars a year. And they have blocked some of the compromises that might smooth the passage of a partial Obamacare repeal and health care reform.
As a result, the Republican leadership has had to rely on Democratic votes for the budget, leading to higher spending. Without the leverage of the House bill taxes went up on couples earning over $450,000. The prospects for any substantial legislative reform of health appear dim.
In contrast, the Democratic left is willing to compromise. They all voted for Obamacare, even if it was not a single-payer plan. And I do not recall any substantial opposition to budgets passed in the Democratic Congress. What explains this difference?