The presumptive Republican presidential nominee clarified his statement Wednesday, saying it may have been "mistakenly construed as a call to rescind the Colorado Compact" when all he wanted was a more measured approach - which nevertheless could mean less water for Utah.
But Wednesday morning, after speaking during a water-conservation symposium in the tiny mountain town of Alta, Republican Gov. Jon Huntsman Jr. said he, too, would be open to at least looking at changes to Colorado River law - as long as regional governors lead the way.
That's why Huntsman, a McCain backer, put water on the agenda of the Western Governors Association, which he heads. "We're going to know over the next year whether [the Colorado Compact] is an interest for the governors," Huntsman said.
"It can't be Washington that says the time is right to open the compact," he said. "It's got to be we in the region saying, 'We're having trouble with this or that and, therefore, it's time to re-evaluate the mechanics of the compact.' "
All seven compact states - Utah, Colorado, Wyoming, New Mexico, Arizona, Nevada and California - signed an interim agreement in December to share the pain of Colorado River water shortages, and agreed to ensure that the levels of Lake Powell and Lake Mead are equal.
But more than 20 scientific studies conducted during the past four years show the Colorado is unlikely anytime soon to be at the high level it was in 1922, when the compact was signed.
The states agree the river is overallocated. Yet they are working to ensure they keep all their rights granted under the compact while also saying they don't want to renegotiate it.
The way the compact is set up, the lower-basin states of California, Nevada and Arizona would have primacy in renegotiations because their water rights are senior. The upper-basin states - Utah, Wyoming, Colorado and New Mexico - likely have the most to lose, especially when California cities in the grip of devastating drought are imposing water rationing and Las Vegas and Phoenix continue to see phenomenal growth.
During an interview last Thursday, McCain told The Pueblo Chieftain "there's a movement amongst the governors to try, if not, quote, renegotiate, certainly adjust to the new realities of high growth, of greater demands on a scarcer resource."
He didn't say which governors.
Colorado Gov. Bill Ritter, a Democrat, scolded McCain for his stance, calling it "sheer folly." On Wednesday, he lashed out again during a joint news conference with Sen. Ken Salazar, D-Colo., and Colorado campaign organizers for Sen. Barack Obama's Democratic presidential bid.
Salazar called McCain's statements "dangerously naive" and said opening the compact could cause a water war across the West. "The renegotiation is frankly very scary for us."
Wyoming Gov. Dave Freudenthal, also a Democrat, said Wednesday he was "absolutely astonished" that anyone running for president would suggest a renegotiation.
"The lower Colorado River Basin states have wanted to reopen that compact for years," Freudenthal said in an audio transcript provided by his staff. "They have only one thing in mind when they say 'reopen' and that isn't to give more water to upper-basin states."
* DEREK P. JENSEN contributed to this story.