"Bad mortgages were being backed by Fannie Mae and Freddie Mac, and it was only a matter of time before a contagion of unsustainable debt began to spread," McCain said during an event in Albuquerque, NM.
"This corruption was encouraged by Democrats in Congress, and abetted by Senator Obama."
McCain said he raised the alarm and called for tighter borrowing rules on Fannie Mae and Freddie Mac two years ago, which could have helped stem the crisis.
By comparison, he said, Obama was "silent" while congressional Democrats fought efforts to rein in the mortgage giants.
"As recently as September of last year, [Obama] said that subprime loans had been, quote, 'a good idea.' Well, Senator Obama, that 'good idea' has now plunged this country into the worst financial crisis since the Great Depression," McCain said.