Default and Defeat
You can and, indeed, must compromise with people who disagree with you about the best way to accomplish shared goals. The problem with accommodation comes when core principles are at issue. The current depressing debate about changing the way that inflation is accounted for in Social Security is a case in point. The argument here isn't about ways and means. Technocratic debates about econometrics are beside the point, though they wouldn’t be in a less polarized political situation. The plain fact is that Republicans want to destroy Social Security, and switching to chained CPI is simply an incremental step in that direction. A legitimate compromise would be between measures that make Social Security more generous and others that tend in the opposite direction. As it is, the only options on the table are more or less drastic ways to weaken the system and make it less popular. Under these circumstances, compromise is inevitably defeat.
Policy wonks often make the mistake of evaluating particular measures as if they existed in isolation and weren't part of a larger struggle. In the long run, what matters are values. So far the Republicans have been successful in framing the Social Security and Medicare debate as if these programs were embarrassing legacies from a bygone era instead of concrete embodiments of a national will to ensure a decent life for everybody who plays by the rules. The sad fact is that a great many establishment Democrats actually share the Republican view of things or have decided, as perhaps Obama has, that the majority of the Americans can't really have rights because they don't really have power. Since the government hasn’t been of the people or by the people for quite a while now, it’s a little unrealistic to expect it to be for the people.