This question depends on which political thinkers one considers authoritative. An Individualist would say that there is no moral ground for compromise in any issue because individual moral stances are of vital importance to personal identity and moral honesty. A Collectivist would say that there is always moral ground for compromise because it is moral to suppress the individual's opinion in favor of the collective's opinion.
In general, current thinkers agree that compromise is essential in many cases because without it, no progress can be made. In the United States, the dominant political parties are constantly at odds because they refuse to compromise; because of this, progress is only made when one party or the other fully controls the political process. From a neutral standpoint, it would be important and moral to compromise on issues that affect all citizens in a nation, and to not compromise on issues that are either moral positions of policy, or necessary to ensure national security.