"With the lack of evidence, he might as well also blame aliens from outer space for the fires," the president of the National Institute for Latino Policy, Angelo Falcon, told CNN.
McCain has since clarified that he was not referring to the current fires in Arizona, but to broader concerns that smugglers and illegal immigrants might set off wildfires while crossing the border.
"The facts are clear. For years, federal, state and local officials have stated that smugglers and illegal immigrants have caused fires on our southern border," Brooke Buchanan, Communications Director for McCain, said in a statement, "During the press conference on Saturday, Senator McCain was referring to fires on the Arizona/Mexico border, not the Wallow Fire."
Local parks officials have listed illegal immigrant crossings as one possible cause of fires in the border region generally and McCain's office also pointed to 2006 testimony from a California forest official who warned that smugglers may set fires as a diversion. But McCain's remarks came at a particularly charged political moment, in which unsubstantiated rumors that illegal immigrants were involved in the two fires have spread across the state.
Illegal immigration has also popped up as an issue in recent years on the other side of the fire. A large number of possibly undocumented workers have been instrumental in fighting wildfires in the Pacific Northwest, prompting some to call on the federal government to look the other way on their status.
Update: McCain released a joint statement on his comments with fellow Sen. Jon Kyl (R-AZ), and Reps. Jeff Flake (R-AZ) and Paul Gosar (R-AZ) saying they had been told by Forest Service officials of illegal immigrants' possible role in border fires:
"During our tour of the damaged areas caused by the Wallow Fire on Saturday, we were briefed by senior Forest Service officials, one of whom informed us that some wildfires in Arizona (across our southern border) are regrettably caused by drug smugglers and illegal immigrants. This statement is consistent with what we've been hearing for years, as well as testimony by the Forest Service and media reports dating back as far as 2006."
"While Arizonans continue to face the enormous challenges related to these wildfires, it's unfortunate that some are inserting their political agenda into this tragedy."