The former leader of the free world will be campaigning in Tupelo, Miss., later Friday. The day before he was in Rock Springs, Wyo.

How the mighty have ... toned it down.

Bill Clinton, once his wife's not-so-secret weapon, has since late January staked out a softer role in the campaign. The combative and blunt political warrior voters saw before the South Carolina primary is gone. In his place is a kinder, gentler Bill, wooing voters mostly in far-flung arenas where he's not the main attraction of his wife's campaign.

In Ohio, he spoke in school gyms. In Texas, he addressed supporters in parks and parking lots. His crowds typically number fewer than 500.

Clinton was speaking in Wyoming Thursday ahead of the state's weekend caucuses, telling listeners how Hillary Clinton would establish 10 clean-coal technology projects if elected president in November.

"Some environmentalists don't think we ought to be doing anything with coal, but they're wrong," he said. "Think about it, you could become, maybe, the first totally energy-independent state in the United States."

Clinton's wins in Ohio and Texas Tuesday may have yielded a valuable lesson — going negative on rival Barack Obama can work, so long as her husband's not the one doing it.

A month-and-a-half after the testy South Carolina primary, Clinton no longer criticizes Obama personally, and he has not appeared onstage with his wife since Super Tuesday, Feb. 5. After months during which he seemed to talk as much about his own record as he did hers, his speeches now focus on policy and on his wife's strengths.

On the trail, the former president travels to rural areas and so-called "secondary markets" that receive less media coverage.

He still stumps vigorously for his wife across the country, and her advisers credit him with boosting her support among rural voters, especially men. He also phones through a list of party "superdelegates" almost daily, urging them to back the former first lady. And he has raised considerable cash for her campaign, both at events with the well-heeled and in online appeals to smaller donors.

But campaign aides believe that after months of trial and error, they have finally found a role for the former president that plays to his strengths without needlessly reminding voters of the theatrics of his White House years.

The answer: play the traditional political spouse.

"He was the first to acknowledge after South Carolina that he'd failed to anticipate how he'd be held to a different standard than other spouses," said Mike McCurry, who was Clinton's White House spokesman. "Right now, he's in a place he's very comfortable with. But I'm sure he's biting his tongue a lot."

The former president was facing a Democratic backlash in January, as he was stepping up attacks on Obama.

Robert Reich, former Clinton labor secretary, wrote on his personal blog: "Bill Clinton's ill-tempered and ill-founded attacks on Barack Obama are doing no credit to the former President, his legacy, or his wife's campaign. Nor are they helping the Democratic party."

Other Democratic standard-bearers aired similar concerns. Al Sharpton even called on him to "shut up."

Clinton's swipes at Obama had reached a fever pitch before fizzling out altogether.

In December, he suggested voters would be taking a "risk" with Obama, during an interview with Charlie Rose.

"In theory, we could find someone who is a gifted television commentator," Clinton told Rose. "And let them run. They'd have only one year less experience in national politics (than Obama)."

Then before the Jan. 8 New Hampshire primary, he called Obama's opposition to the Iraq war a "fairy tale. "

Then came South Carolina, where he lectured reporters on their alleged bias toward Obama, and suggested an Obama victory would be race-based. In a parting shot, Clinton even noted that Jesse Jackson won there 20 years ago.

After Super Tuesday, Clinton said he'd learned his lesson.

"I think I can promote Hillary but not defend her because I was president," Clinton said in an interview with NBC affiliate WCSH-TV as he was campaigning in Portland, Maine. "I have to let her defend herself or have someone else defend her."

Timeline: Where's Bill?

Feb. 28: Smithfield, R.I.

Feb. 29: Wooster, Ohio

March 2: College Station, Texas

March 3: Corpus Christi, Texas

March 4: San Marcos, Texas

March 6: Rock Springs, Wyo.

March 7: Tupelo, Miss.

The Associated Press contributed to this report.