Irony lurked in the Cable News Network anchor booth overlooking the Republican convention as guest commentator John Connally sat with me watching Gerald Ford mount the podium for an ex- president's speech which, but for a glitch in the course of history, might have been his own.

While Ford spoke, the former Democrat who became President Nixon's Treasury secretary and "closest political adviser," mused off-camera about what might have been.

In 1971 Connally had discouraged Nixon from dumping Spiro T. Agnew from the reelection ticket and naming him as running mate. When Agnew resigned in disgrace in October 1973, Connally was Nixon's first choice for successor in a field of four. The others were Ronald Reagan, Nelson Rockefeller and Gerald Ford.

In the end, Nixon settled on Ford because his congressional background would facilitate early confirmation. But Nixon told Ford bluntly -- and Ford repeated to Connally -- that the new vice president should have no illusions about 1976. Connally was Nixon's choice for successor as president. And, said Connally, Ford promised to retire in 1976 and support him for president. It didn't work out that way.

Looking down from the glass enclosure across a sea of delegates to the distant figure on the podium, Connally said he bore Ford no hard feelings. I thought this footnote to history more interesting than much of what was happening on the convention floor, but Connally declined to be interviewed on the subject on the air.

Ford, however, was willing to talk about it. Interviewed the next day from his Dallas hotel suite on CNN's "Take Two" program, Ford confirmed much of Connally's account, though the details differed. Ford said his promise to back Connally for the presidency had been given in a different connection some seven months before the Agnew resignation.

He had informed Connally, over breakfast in Palm Springs, Calif., in March 1973 of his promise to his ailing wife to retire from Congress in 1976 after serving one more term. Ford said Connally, who was about to resign from the Nixon Cabinet, discussed the possibility of a 1976 presidential candidacy, and "I was very supportive."

Then, in October, came the sudden offer of the vice presidency. "President Nixon told me," said Ford, "that he was for John Connally in 1976. He wanted to forewarn me that if I, as vice president, wanted to run for president, he would be supportive of Connally. I said that didn't bother me at all because some months before both Betty and myself had decided that I was going to run for Congress one more time and I was going to leave public office of my own volition.

"So I had no ambitions, in 1973, when President Nixon nominated me for the vice presidency, to take the vice presidency as a stepping stone for a candidacy for the presidency."

Ford's implication was that his commitment was limited to not running for president as vice president. It had not been foreseen that Nixon would be forced to resign in August 1974, leaving him no longer in a position to anoint his successor and Ford facing 1976 as the incumbent president.

All this left a host of "what ifs" to ruminate about. What if Nixon had obeyed his original impulse and nominated Connally instead of Ford as vice president? What if it had been President Connally instead of Ford against Jimmy Carter in 1976? Could he have been more successful? Or would he have been also hurt by a Nixon pardon, as well as his facing charges of accepting a milk fund bribe (of which he was acquitted in a 1975 trial)? And, if elected, in 1976, would Connally have been reelected in 1980 and would he then have been in Dallas overseeing the nomination of his own successor?

What if?

Instead, Connally made an unsuccessful primary race in 1980. And now, from a television booth, he was observing the cavalcade of Republican politics that had passed him by.