He was NOT lazy; his command of policy equaled or exceeded that of his rivals, and he was, as he said, pretty clearly a consistent conservative for his public life. But his staff was poorly managed; it started much too late; his campaign was riven by internal fueds and suspicions: one faction accused the other of leaking to reporters.
He had a nomination strategy that was plausible enough: do well in Iowa, build a bridge to South Carolina, earn delegates everywhere, defeat a single rival handily on Feb. 5 in the Southern states, and earn the establishment's backing.
Demographically, he alienated Republican women. Mike Huckabee effectively shut off his support in Iowa and South Carolina. In truth, he could have campaign a little more and emphasized retail, rather than stump speeches. He did not raise as much money as he could have, in part because so many donors wondered whether his heart was in the race.
And in many ways, he tried to occupy a space that John McCain more credibly occupied; national security strength, straight talk on the economic challenges facing the country and resiliency.