The epidemic of 20 or more nationally televised debates has turned the 2012 presidential campaign into a political reality show. Tomorrow's installment in Arizona, in advance of its Feb. 28 Republican primary, will be the last before Super Tuesday on March 6, when 10 states will vote.

Just when you thought the debate mania of the current campaign might never end, one or more of the four surviving candidates seem to be having second thoughts about the value and wisdom of so many talkathons. As a result, the one planned for March 1 by CNN in Georgia has been scrapped, with Mitt Romney the first to pull out, followed by Ron Paul.

The decision is a particular blow to Georgia homeboy Newt Gingrich, who achieved his earlier resurrection by bashing the news media in previous debates. No doubt, he was anticipating another chance to strut his stuff in front of a large television audience before the Georgia primary on Super Tuesday.

The debates, while giving voters a storehouse of information about all the candidates, also have increasingly turned into verbal wrestling matches of personal negative assaults. They have been damaging not only to the candidates but also to public respect for them, and for the process.

Poor debate performances have driven the likes of Rick Perry and Michele Bachmann from the campaign in the normal winnowing out of the primaries and caucuses. However, the increasingly bitter tone of the exchanges, particularly between Messrs. Gingrich and Romney, may have convinced Mr. Romney's strategists that the debates have become too much of a good thing.

Mr. Gingrich, with his reputation as a take-no-prisoners campaigner, has little to lose in continuing in that vein. He may be oblivious, in his self-important arrogance, to the wounds he inflicts on his own prospects, in the wake his brief comeback in the South Carolina primary before sliding again in the polls.

Mr. Romney, on the other hand, in returning Mr. Gingrich's fire, may have shown previously undisclosed backbone, but in doing so he has often seemed in conflict with his otherwise sunny and even patronizing manner. As an attack dog, he appears to be trying too hard, just as he has been seeking to oversell himself as "severely conservative."

As for Rick Santorum, the loss of even one television debate is a setback in his effort to cast the Republican contest as a two-man confrontation between Mr. Romney and himself. His recent small victories in minor primary and caucus contests have finally swung the spotlight toward him.

Even another four-man debate is preferable to Mr. Santorum in a Republican fight that has become dominated by negative television advertising, financed in the millions of dollars by the Romney and Gingrich super PACs and turning the campaign into mudslinging excess.

A diminution in the number of nationally televised debates could have a constructive effect on the Republican campaign if only by denying the trailing candidates a free lifeline to continuing in the competition. As long as the multicandidate debates continue, the prospect soon of a two-man televised faceoff between Mr. Romney and the surviving anti-Romney challenger seems unlikely.

Meanwhile, President Obama, as the unchallenged Democratic nominee for re-election, can stand aside, watching the Republican hopefuls highlight each other's political vulnerabilities in both debates and paid advertising. Not content with this role as spectator to the carnage in the opposition camp, Mr. Obama has decided to encourage Democatic participation the mad money chase of corporate and other "unaffiliated" political action committees polluting the airwaves with their ads, and hence the election process itself.

We can all hope that when the general election arrives, the now-established tradition of limited debates involving the major-party presidential nominees and their running mates will again kick in. By that time Mr. Gingrich and his pipedream of seven Lincoln-Douglas type debates will be forgotten, if not the irrepressible dream-chaser himself.

The independent Commission on Presidential Debates, sanctioned by both parties, is approaching its 25th anniversary celebration, and after some early difficulties it has achieved institutional status. In its hands this fall, without the often glitzy staging seen this year in network and cable hands, the debates should see a welcome return to sanity.

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 juleswitcover@comcast.net.