If the Republican field had been smaller, and weak candidates had not lingered so long, it's doubtful Romney would have come out ahead. The conservative vote was strong but just split too many ways.
The "conservative vote" was also without a conservative champion to vote for. All of the so-called conservative candidates were seriously flawed. Each of Newt, Santorum, Perry, Bachman, et al had shortcomings that as candidates...and as conservatives.