Washington ? What began as one mother’s vigil on a country road in Texas two weeks ago has grown into a nationwide protest, putting a grieving human face to the miseries of war and growing misgivings about President Bush’s strategies in Iraq.

It’s still not clear whether Cindy Sheehan’s effort was the start of a lasting anti-war movement or a fleeting summertime story fueled by media-savvy liberal interest groups.

Sheehan said Thursday she was leaving, rushing to the side of her mother who had had a stroke in California. She said she would be back if possible before Bush leaves his ranch for Washington on Sept. 3.

Whatever happens to the Texas vigil, Republican Party leaders are worried that the so-called “Peace Mom” has brought long-simmering unease over Iraq to a boil by galvanizing anti-war activists. They fear that protests will strike a chord with the large number of Americans who have long felt uneasy about the war yet have been giving Bush the benefit of the doubt.

The president’s falling poll numbers – less than 40 percent approve of his handling of Iraq – could drop further, threatening his military plans in Iraq, his agenda at home and Republican political prospects in the 2006 congressional and gubernatorial elections.

Peter Smith and Deb Epperson stand on the lawn of City Hall in Flagstaff, Ariz., with the Stars and Stripes during a candlelight vigil Wednesday in support of Cindy Sheehan. Sheehan, whose son Casey died in Iraq last year, started a protest Aug. 6 in memory of her son.

But will that happen? Will one woman’s demand to meet the president outside his vacation home be viewed someday as a tipping point against the war?

“It’s really hard to tell whether this will be a blip on the radar screen or whether it reflects a deep change in public opinion,” said John Green, director of the University of Akron’s Ray C. Bliss Institute for Applied Politics. “A lot will depend to what extent Sheehan and her vigil link up with the disquiet we’re seeing in public polls, especially with the people who haven’t been opposed to the war in the past. That possibility has made Republicans nervous.”

It also depends on factors outside the control of Bush, Sheehan and their supporters. A reduction in violence in Iraq or a legitimate, new constitution for the government would help Bush. More bloodshed and no political progress in Iraq would probably give momentum to Sheehan and her supporters.

A change of subject might help Bush, too. He has a ready-made page-turner awaiting his return from Crawford, Texas, when Senate hearings begin Sept. 6 on the nomination of John Roberts to the Supreme Court.

No matter what happens, it can’t be denied that Sheehan thrust herself and her cause into the spotlight at near-record speed.

The vigil began Aug. 6, when she showed up outside Bush’s ranch with 50 demonstrators to demand a meeting. “I want to ask the president, ‘Why did you kill my son? What did my son die for?”‘ she said.

Her son, Casey, 24, was killed in Sadr City, Iraq, on April 4, 2004.

Less than a week into the vigil, the president gave Sheehan’s protest a public relations boost by talking about it. He told reporters that while he sympathized with her, her call to withdraw U.S. troops “would be a mistake for the security of this country.”

MoveOn.org and other liberal interest groups used the Internet, e-mails and cable TV news coverage to keep the protest in full view. Normally slow news cycles of August were filled with stories about Sheehan and her fallen son – an altar boy, Eagle Scout and church youth troop leader.

Even before the vigil, public opinion was shifting against Bush and the war. An AP-Ipsos poll showed a majority of people questioning the president’s honesty. A Gallup Poll suggested that nearly six in 10 wanted some or all U.S. troops to be withdrawn.

Bush’s own advisers began to privately acknowledge that Americans were finding their views on Iraq out of sync with his upbeat rhetoric.

Confronted by anxious constituents during their August recess, a few GOP lawmakers joined several Democratic in denouncing the war. Some Republicans who favor the war urged Bush to do a better job defending it.

“I don’t want to be critical of the White House, but the key is to put the Iraqi campaign in the context of a regional struggle that includes elements in Syria, Saudi Arabia and Pakistan, and then put that in the context of the larger struggle against the irreconcilable wing of Islam,” said former House Speaker Newt Gingrich, a potential 2008 presidential candidate.

Sheehan has not gotten her meeting with the president in Texas. Bush’s supporters note that he met with her in 2004, and that she had nice things to say about him at the time. That’s half of the story.

Indeed, after that 2004 meeting, Sheehan was quoted as calling Bush sympathetic and sincere, a man of faith. But she also sharply stated that she wasn’t happy with the way the war had been handled, and accused Bush of changing his rationale.

What happens in Iraq the next weeks and months may determine whether the “Peace Mom” finds her own place in history, or becomes a footnote.