Mr. Romney first failed to win the GOP nomination in 2008 as a moderate governor of heavily Democratic Massachusetts. Four years later, he shed the middle-road path followed by his late father, George Romney, who won three terms as governor of Michigan but failed to win the Republican presidential nomination in 1968.
That year, the father hewed to the moderate course but was easily outmaneuvered by Richard Nixon, who seized both the center and right wing of the party. By the time son Mitt became the GOP standard-bearer 44 years later, moderate Republicanism was not merely a shadow of its former self but virtually a ghost.
So Mitt Romney simply changed his ideological spots. The transformation was a manifestation of how the party had evolved over half a century. It went from the orthodox conservatism of Sen. Robert A. Taft of Ohio to the centrism of Richard Nixon, and then to the extremism of Barry Goldwater and his more pragmatic 1964 cheerleader, Ronald Reagan, in1980.
Along the way, the liberal Republicanism of Nelson Rockefeller and Jacob Javits came and went. Eventually, only a few GOP moderates, such as Maine Sens. Olympia Snowe (now retired) and Susan Collins, were left to carry the fallen standard of bipartisanship against the onslaught of right-wing evangelicals and anti-establishment tea partiers.
This devolution of moderate Republicanism was well chronicled in 2012 in "Rule and Ruin: The Downfall of Moderation and the Destruction of the Republican Party, from Eisenhower to the Tea Party," by political scientist and historian Geoffrey Kabaservice.
The book traced the erosion of moderate influence after the Eisenhower presidency, and how the conservatism and anti-intellectualism of Goldwater, after surviving the Nixon years of accommodation with all factions, blossomed under Reagan and more destructively under George W. Bush.
It underscored how Nixon first achieved a centrist image with such initiatives as revenue-sharing with the states at home and his opening to China abroad, as well as his de-escalation of the American combat role in Vietnam.
Nevertheless, the author wrote, "Nixon's rhetorical conservatism, his willingness to polarize the country around controversial social issues, and his abuse of his office and the rule of law made moderates turn against him. Watergate depressed the faith that Americans had in government generally, which ultimately damaged moderate Republicans as well as liberal Democrats."
At the same time, Mr. Kabaservice noted, the moderate Ripon Society believed that "only progressive Republicans, unscathed by the scandal" could "restore to the party an image of integrity and objective government," optimistically proclaiming "the combination of independence, intelligence and integrity makes them ideal for party leadership."
But even before Watergate, the GOP moderates had failed to identify and boost a credible party leader who could withstand the Nixon-Agnew mobilization of the so-called "Silent Majority" of anti-liberal, anti-government naysayers in which right-wing conservatism flourished.
In Watergate's aftermath, the party temporarily fell to Nixon's standby, the congenial Gerald Ford, who leaned on conservative support to the degree that he acquiesced in the dumping of his hand-picked vice president, liberal Nelson Rockefeller, and still lost in 1976.
In 2000, party moderates who allowed themselves to be lulled by George W. Bush's "compassionate conservatism" were soon driven off by his 2003 invasion of Iraq and nation-building misadventures there and in Afghanistan.
The author of "Rule and Ruin" concluded : "The Bush years demonstrated anew that conservatives were skilled at politics but deficient at governing, and that a Republican Party without moderates was like a heavily muscled body without a head. ... If moderation remains long absent from one party, let alone both, the consequences are likely to be dire. ... Political movements based on dogmatic, unthinking certitude may be fatal to American values."
The GOP's surviving moderates in 2012 conceivably might have found their savior in the old Mitt Romney. But not in the once-moderate leopard who changed his spots to be an acceptable fit in the party that by now bears little resemblance to his father's middle-road political home.
Jules Witcover is a former longtime writer for The Baltimore Sun. His latest book is "Joe Biden: A Life of Trial and Redemption" (William Morrow). You can respond to this column at firstname.lastname@example.org.