SANTA ANA, Calif.  Drawing a sharp distinction between himself and the two Democratic presidential candidates, Senator John McCain of Arizona warned Tuesday against vigorous government action to solve the deepening mortgage crisis and the market turmoil it has caused, saying that “it is not the duty of government to bail out and reward those who act irresponsibly, whether they are big banks or small borrowers.”

Mr. McCain’s comments came a day after Senator Hillary Rodham Clinton of New York called for direct federal intervention to help affected homeowners, including a $30 billion fund for states and communities to assist those at risk of foreclosure. Mrs. Clinton’s Democratic opponent, Senator Barack Obama of Illinois, has similarly called for greater federal involvement, including creation of a $10 billion relief package to prevent foreclosures.

As the foreclosure crisis has rippled across the economy, it has thrust itself to the forefront of the presidential race, with Democrats seizing on the issue in urging forceful government steps to alleviate the crisis. Mr. McCain’s remarks Tuesday, to a group of Hispanic businessmen here, signaled a sharpening divide between the two parties’ candidates, with the senator warning against quick, costly government fixes to a crises rooted in the private sector.

“Rampant speculation” on both sides is the root cause of the crisis, Mr. McCain said. He placed part of the responsibility for the mortgage mess on lenders, who he said had grown “complacent” in a rising market and as a result acquired a “false sense of security” that caused them to “lower their lending standards.”