When he formally announced his presidential candidacy last year, Sen. John McCain was inches away from making an unprecedented pledge: if he were elected, he would serve only one term as president.

It could have been an earth-shifting moment for the campaign and the primary. At the time, McCain’s fundraising pace was falling well short of its target and Republicans were not treating McCain as the frontrunner.

The idea to serve one term had long been discussed among top advisers, and McCain was on board.

A one-term pledge was set to be the central thread of his presidential campaign, and Mark Salter, McCain's chief speechwriter, crafted an announcement speech around it.

But less than a day before he was set to speak in New Hampshire on April 25, McCain ordered his aides to excise the paragraphs describing the pledge.

"Lots of ideas get raised with the candidate. He made a decision and we didn't do it," Salter said in a brief telephone interview this afternoon. He said that "no speech is final until the candidate signs off."

Several of McCain's closest friends, including former Sen. Phil Gramm (R-TX) and Sen. Lindsey Graham (R-SC) had urged him not to tie his hand by making a one-term pledge, and McCain agreed with them.

McCain’s announcement speech, in Portsmouth, included several hints of the theme. McCain said “won’t judge myself by how many elections I’ve won, but by how well I’ll keep my promises to you.” He said he’d “challenge myself and each member of Congress to wake up each morning and ask ourselves: will we remember today as the finest day of our public life.” He said he did not “seek the office out of a sense of entitlement.”

Salter said that "no speech is final until the candidate signs off."

Campaign advisers said that, as they discussed the merits of the pledge, the drawbacks were obvious: it might tie McCain’s hand with Congress. It would certainly raise the profile of his heir apparent and vice presidential nominee, who would be treated as a de-facto presidential candidate for McCain’s entire term. And it would draw attention to his age.

But at the time, the benefits were judged to be equally as powerful: his finance team loved it; it would call more attention to the political opportunism of his opponents, Republicans and Democrats. It would free him from having to spend the last two years of his presidency running for re-election; it would send an unmistakable message that McCain intended to be a different kind of president. One Republican close to the campaign said: “It would have been the most selfless act in modern American politics.”

Current McCain aides declined to comment, and former members of his staff who were in a position to know – former senior strategist John Weaver and ex-campaign manager Terry Nelson, declined to comment. Republicans familiar with the situation said that fewer than a dozen senior McCain aides and fundraisers were aware that McCain planned to take the pledge.

Several Republican activists and bloggers have urged McCain to take the pledge, including Ramesh Ponnuru, a National Review editor who is close to McCain advisers. “It would highlight his devotion to service,” Ponnuru has written.

One aide said that a one-term pledge “hasn’t been discussed” for at least a year.