Which of a long list of shortcomings doomed Rick Perry's campaign for the presidency? Certainly, he is among the world's worst debaters, a dim-bulb on foreign policy and a right-wing theocrat whose "pro-life" credentials stop short of fair trials for defendants in capital murder cases.
But similar attributes were not early disqualifiers for Herman Cain. Why didn't Perry's tenure in Texas and his stature among social conservatives keep him aloft longer?
Perry's undoing may have been the moment that -- for me, anyway -- was his best in a series of embarrassing debate performances: his stand-up defense of the Texas policy that allows undocumented students to pay the same rates of tuition that legal residents of the state pay to go to college.
"... The bottom line is, it doesn't make any difference what the sound of your last name is. That is the American way," Perry said in a Sept. 12 debate.
He went on to remark that those who oppose the policy "don't have a heart," drawing boos from some in the audience. Immediately, the blogosphere and Twitterverse lighted up with denunciations of Perry from the right and predictions that his campaign was done.
Since then, the only Republican candidate who has dared come close to enunciating an immigration policy with a smidgen of compassion or common sense has been Newt Gingrich, who has suggested that longtime illegal workers with family ties to U.S. citizens be given special consideration. Gingrich's rivals have adopted positions that range from cavalier to cruel toward the unauthorized workers who have filled a critical void in the American labor force.
That includes ideological chameleon Mitt Romney, who staked out a hard-right immigration position as early as the 2008 campaign. Recently, he proudly announced the endorsement of Kris Kobach, the Kansas secretary of state who has helped shape the harsh immigration laws passed by GOP-dominated state legislatures over the past two years.
That's good for President Obama, of course. He has disappointed many Latinos with his failure to achieve comprehensive immigration reform and his insistence on a deportation policy that rounds up both hardened criminals and hapless unlicensed drivers.
But compared to Romney and the other GOP contenders, Obama has been a champion of Latino interests. And they are likely to respond by throwing their wholehearted support to the Democratic ticket, as they did in 2008.
So why doesn't that sound like good news to an unabashed liberal who is appalled by the modern-day Republican Party? Because I've observed carefully what happens when one of the major political parties conscientiously goes about making itself anathema to a significant voting bloc, and the results are not exactly a boon to democracy.
Ever since Barry Goldwater made resistance to the Civil Rights Act a pillar of his 1964 campaign for the presidency, Republicans have been honing the Southern strategy -- appeals to white voters who still resent full equality for black citizens. Since then, every Republican candidate for president has used some version of that strategy.
Black voters have noticed and have largely written off the Republican Party. In turn, Republican politicians have become further estranged from black voters, refusing to cater to their interests or even campaign for their support. The current political era of vicious polarization has many causes, but the estrangement between black voters and the Republican Party is certainly a contributing factor.
Despite the best efforts of some of the GOP's leading strategists, who have warned against alienating a growing ethnic group, the party seems headed in the same direction with Latinos, championing harsh rhetoric and mean-spirited policies that will poison relations with that voting bloc for generations. That's too bad.
The Republican Party will come to its senses sooner or later, as changing demographics inevitably force it to come to terms with a browning America. Until then, though, we're in for a few more campaign cycles of race-baiting, scape-goating and polarization.
Cynthia Tucker, winner of the 2007 Pulitzer Prize for commentary, is a visiting professor at the University of Georgia. She can be reached at cynthiacynthiatucker.com.