However, there are significant differences between then and now that suggest the GOP is paying a much bigger price for its circular firing squad among Mitt Romney, Rick Santorum, Newt Gingrich and Ron Paul than the Democrats did in their two-sided primary fight four years ago.
Most obvious and significant is that, for all the heat generated by Mr. Obama and Ms. Clinton, they differed relatively little on major issues. To the extent that party ranks split, it was over personal appeal and loyalty, not rock-bottom principles or arguments over which of them was the true-blue Democrat.
Second, both Mr. Obama and Ms. Clinton had the political credentials that established them as bona fide serious candidates, and each had a built-in base to sustain the competition. Mr. Obama ran as the first African American with a realistic chance of being elected, and Ms. Clinton as the first woman similarly positioned.
When their hard-fought battle for the nomination was over, the competitors found a ready path to come together in the general election, and the bulk of Ms. Clinton's supporters got behind Mr. Obama. The healing was so successful that after all the votes were in, the primary loser became the winner's secretary of state, the top cabinet post he awarded.
Compare those two competitors with the rinky-dink band of Republican aspirants this year. None of them has been thoroughly embraced within their own party, and two of them, Messrs. Gingrich and Paul, are pure poison to some segments of the GOP.
Then there is the undistinguished longshot Mr. Santorum. A weak loser for re-election to the Senate from Pennsylvania six years ago, he is now trying to ride faith and ideological purity to the presidential nomination amid wide Republican fears he could never beat President Obama.
The fact is that all four surviving candidates in the Republican mud bath, including Mr. Romney, are being diminished by throwing caution to the winds in trying to ward off the attacks on them from within the party. And, unlike Mr. Obama and Ms. Clinton in their fight, the Republican contenders have had their arsenals stocked by millions of dollars from the super PACs, thanks to the Republican-led Supreme Court's ruling that threw open the floodgates to unlimited corporate campaign contributions.
It may well happen that the 2012 losers in the Republican presidential nomination quest will fall in line behind the winner, as Hillary Clinton did for Barack Obama four years ago. But the bitterness expressed by the four GOP warriors against each other in an unprecedented series of television debates has already left a bad taste with many voters, and it is likely to linger.
A Republican Party whose primary and caucus voters have been so reluctant to rally around Mr. Romney -- and so willing to back a tainted challenger like Mr. Gingrich or a narrow ideologue like Mr. Santorum to block or just slow his slog to the nomination -- could be unable to arouse itself sufficiently to elect him in November.
The fiercely expressed determination in GOP ranks to oust Mr. Obama, voiced repeatedly by Senate Minority Leader Mitch McConnell in his battle cry to make him "a one-term president," seems to have lost some of its zeal amid the civil war for the party nomination. The wish may be undiminished, but the conviction that it will be achieved now lacks the previous certitude.
The same Republican ambivalence that existed over John McCain's prospects for beating Mr. Obama as the election drew closer in 2008 now clouds entire field of GOP aspirants. The doubts may be even greater because of the spectacle they have made of themselves in their divisiveness.
The famous comment of old baseball manager Casey Stengel, who was trying to make a team out of the fledging and hapless New York Mets in 1962, comes to mind: "Can't anybody here play this game?"
Jules Witcover is a syndicated columnist and former long-time writer for The Baltimore Sun. His latest book is "Joe Biden: A Life of Trial and Redemption" (William Morrow). His email is email@example.com.