Momentum. A win or a good showing in three states translates to a big bump in later primaries. Unlike many of the posters here on FR, most republican and independant voters will vote for the guy they think is most likely to win. They want Obama gone and will vote for the guy they perceive as the most likely to get that done.
If most Republican voters believe the media (once again), then we will get exactly what we deserve, likely 4 more years of Obama. I don't subscribe to the ABO strategy being successful, especially when the Obama opponent is historically a Moderate to Liberal candidate who's track record (as a Governor) bears a striking resemblance to Obama’s