I don't know how many they were, but I suspect there were a fair number of voters who convinced themselves that Romney's recent right wing extremism was just for the sake of placating Tea Party activists and winning the Republican nomination. They comforted themselves by predicting that, if he became president, he would drift back to the moderate to liberal Republicanism of his gubernatorial days.
His selection of Paul Ryan as a running mate dashes whatever tiny chance there was of that happening. The billionaires who dictate contemporary Republican radicalism had their way. True, I don't believe Romney is an ideologue like his new running mate. He's just a weaselly opportunist, totally willing to take whatever orders the plutocrats care to issue if that's what it takes to win.