There are some real signs in the polling that the Republican base has finally come around to settling for Mitt Romney. Frank Newport at Gallup finds that the wild swings in the race appear to have ended.

Based on the past historical record, we might have thought that Santorum would have surged back into the lead on the back of the national visibility of his two Southern wins. That is what has happened in the past: A candidate wins a primary or set of primaries, and he moves ahead nationally. Romney moved ahead after New Hampshire. Gingrich moved ahead after South Carolina. Romney moved ahead again after Florida.  Santorum moved ahead after wins in Minnesota, Missouri, and Colorado. But this time, Santorum was not able to take advantage of his Deep South wins for national gains. We saw hardly a ripple in our national tracking. Romney’s lead remained remarkably constant during this period. As noted, this could be a sign that Romney is gaining more stability in his standing among Republicans nationally. My colleague Lydia Saad will have more on this Tuesday at Gallup.com.

For most of the primary battle the race has been dominated by erratic swings.  A non-Romney candidate would shoot into the lead ahead of Mitt Romney because of a primary win or even a single good debate performance, only to have their support collapse just as quickly. In just the past three months Romney has briefly lost the national lead twice only to recover it just as quickly.  But it now looks like Romney’s national lead is becoming relatively solid.

The trouble for Romney though is that he still seems unable to break his roughly 38% ceiling which he has bumped into repeatedly but never passed. That is good enough to put him ahead of his three rivals, but it makes it very tough for him to  acquire delegates faster given the proportional nature of most contests. It is still going to be a very long slog for Romney to get to 1,144 delegates.