Geoffrey Kabaservice is the author of Rule and Ruin: The Downfall of Moderation and the Destruction of the Republican Party, from Eisenhower to the Tea Party.

When Bill Clinton suggested last week that Mitt Romney’s position on the auto bailout must have caused his father, former Michigan Governor George Romney, to be “turning over in his grave,” he was being deliberately provocative. But he was also being too kind.

After all, it’s not just Mitt’s stance on auto manufacturing that would have caused his father grief. He has repeatedly cited his father as his greatest personal and political influence, and his principal motivation in seeking the presidency, as best anyone can determine, is to avenge his father’s failed 1968 attempt; yet the irony of Mitt’s campaign is that, despite his heartfelt loyalty to George’s memory, he seems to lack any real understanding of, or sympathy for, his father’s principles.

SQUINT A LITTLE and Mitt looks a lot like his father, with the same lantern jaw, large forehead, and dark upswept hair graying at the temples. Mitt also resembles Romney père in his devout Mormon faith and business success before entering politics. And both Romneys acquired a reputation as pragmatic Republican governors, George in Michigan, and Mitt in Massachusetts.

But the apparent similarities between the two Romneys turn out, upon closer inspection, to be sources of difference. While both father and son were deeply influenced by their Mormon upbringing, for example, George was more strongly marked by the religion’s turbulent origins. George was born in a Mormon colony in Mexico founded by his grandfathers, who had fled the United States rather than abandon the practice of polygamy. He was one of the 207 grandchildren of those prolific patriarchs. His parents, who were not polygamous, lost everything when Mexican rebels confiscated their property. They returned destitute to the U.S., and George experienced poverty and hard labor while growing up. Mitt, by contrast, was raised in affluence, and the family history of exile and struggle was only a distant ancestral memory.

And while both Romneys enjoyed successful business careers, George’s leadership of the American Motors Corporation (AMC) gave him a very different skill-set from Mitt’s at the private-equity firm Bain Capital. Mitt never attempted to take to the airwaves to try to change consumers’ thinking, as George did in his efforts to sell the public on the merits of compact cars such as the AMC Rambler, or to engage in the give-and-take of slugging it out with unions. George’s flesh-pressing efforts to win over auto workers on the factory floor gave him a comfort with personal interactions with ordinary voters that his son seems to lack....