Barack Obama's vow to quell "slash and burn" politics, which helped sweep him to the presidency, is facing a decisive test in the angry echo-chamber imperiling his health reform drive.
"Do we participate in a politics of cynicism, or do we participate in a politics of hope?" Obama asked in the 2004 Democratic convention speech which rocketed him into the public eye.
Fast-forward five years to the sound and fury of the health care debate, and that message is struggling to be heard above a cacophony of negative advertisements and fulminating voters at lawmakers' town hall meetings.
It seems inevitable that Obama will be a changed president when he emerges from the tumult over his plans to offer health care to 46 million uninsured, cut costs for those who have policies and rein in insurance giants.
A famous victory on health care, which eluded previous Democratic presidents, would embolden Obama's change agenda and validate his core political creed and personal brand.
But should his plan end up in the graveyard of failed big-ticket presidential initiatives, tough questions will be asked.
Some will likely argue Obama's crusade for hope and change has been exposed as naive, or "all hat and no cattle" as his foe-turned-ally Hillary Clinton said in their bitter primary campaign.
Should Congress pass a messy compromise, second guessers will question Obama's strategy, and despite a string of early legislative wins, his political aura will dim.
Obama makes no secret of his disdain for buzzsaw spin tactics, but the unflinching attack politics of his Republican critics do seem to be framing the debate.
"The difficulty is, that style of politics, does not match up really well with the issue at stake," said Dante Scala, a political scientist at the University of New Hampshire.
"Everybody has a stake in (health care) and when that happens, the temperature goes way up."
Could it be that Obama overestimated his ability to heal deep political divides in US society which are playing out over healthcare?
"Change is never easy," the president said in Colorado, on a tour of western states which ended in Arizona.
Andrew Dowdle, professor of political science at the University of Arkansas argued that Obama could fall short.
"I think he really underestimated the long-time split in American society, just chalking it up to personality difficulties with Bill Clinton or George W. Bush," Dowdle said.
Obama's foes, like Republican ex-vice presidential hopeful Sarah Palin, have condemned his plans as "evil" and a "socialized" grab at American freedoms, claiming wrongly that he wants "death panels" to ration end-of-life care.
This, Obama aides argue, is the ranting of an extreme fringe, noting the fury of Palin's election rallies did little to stem the president's near-landslide in November.
Republicans have also profited by mining genuine suspicion of government endemic in US society, to hammer the idea of a "public option", a federal entity which would compete with private insurers to offer health benefits.
Now Liberals will likely be outraged at signs Sunday the administration is stepping back from such a proposal.
White House sources are confident some version of health care reform, no less than five plans are in Congress, will pass this year.
But what if the fight gets so fierce over lawmakers' August breaks that momentum for reform dies?
Democrats still shudder at the crippling impact of Clinton's failed health reform drive, while some analysts draw parallels at early setbacks which helped doom Jimmy Carter to a one-term presidency.
Failure would cast doubt on Obama's ability to build congressional majorities to pass priorities like climate change legislation for instance.
That could bleed political momentum and unite Republicans as Democrats defend congressional majorities in 2010 and Obama faces reelection in 2012.
"My sense is that the stakes are high for failure here," said Scala, assessing sentiment of Democratic voters.
"What are you going to come out to vote for in 2010 if you didn't get health care passed, if you had majorities in both houses of Congress and you have the presidency?"