With all the focus in the Republican presidential race on former Massachusetts governor Mitt Romney’s struggles with conservatives, we got to wondering about the other end of the ideological spectrum within the Republican party.

Put simply: How many Republicans identify themselves as moderates or liberals in exit polling conducted in the 2012 race to date? And are there enough centrists in the party to deliver Romney the nomination?

Thanks to the terrific Washington Post polling team — follow them on Twitter @postpolls — we got some answers.

The low water mark for moderates/liberals is 17 percent of the electorate in both Iowa and Nevada. That’s not surprising given that both states held caucuses, which tend to attract a smaller number of very conservative voters than do primaries.

The largest contingent of moderate/liberal voters came in Vermont (53 percent of the overall electorate) followed by Massachusetts (49 percent) and New Hampshire (47 percent). Also, not surprising as the Northeast has long had the reputation as the home of the moderate wing of the GOP.

The average percentage of moderate/liberal Republicans across the 16 states listed above is 33 percent, meaning that either “somewhat” or “very” conservative voters comprise the other 67 percent. (Math!)

Former Massachusetts governor Mitt Romney has won the moderate/liberal vote in 14 of the 16 states. He lost that group to N ewt Gingrich in the former House Speaker’s home state of Georgia and to Texas Rep. Ron Paul in Iowa. (Romney and Paul each won 50 percent of the moderate/liberal vote in Virginia.)

Even the most cursory glance at those numbers reveals that Romney can’t hope to win the Republican nomination by relying on his strong support among those who see themselves in the ideological center of the Republican party. There simply aren’t enough moderate and liberal GOPers to bring Romney even close to a majority — with the possible exception of a handful of states in the Northeast and on the West Coast.

In order to clinch the nomination, Romney must not only consolidate his support among the 33 percent (or so) of Republicans who describe themselves as moderates or liberals but also find a way to win more of the conservative vote. Romney will never be the favorite of a majority of conservative Republicans but he simply can’t afford to lose them as badly as he has been and hope to beat Santorum in states outside of the coasts of the country.