The debate questions, which focused on a series of controversies and comments involving Obama, drew complaints on Thursday from the Illinois senator and from viewers.
"I know some of my opponent's supporters and my opponent are complaining about the hard questions," Clinton, a former first lady, told a rally.
"Well, having been in the White House for eight years and seeing what happens in terms of the pressures and the stresses on a president, that was nothing," she said.
Referencing a famous quote from folksy former Democratic President Harry Truman, Clinton said: "I'm with Harry Truman on this.
If you can't stand the heat, get out of the kitchen." Clinton, who has complained about moderators' treatment of her in previous debates, is in a hard fight with Obama for the Democratic presidential nomination to face Republican John McCain in November's presidential election.
The two face off next in an important primary vote in Pennsylvania on Tuesday.
Obama Fires Back
Obama spokesman Bill Burton accused Clinton of hypocrisy.
"Considering the fact that Senator Clinton sat on stage at the last debate and complained to all of America that she always gets the first question, her blatant hypocrisy here is stunning," he said in a statement.
The Clinton campaign has often accused reporters of being harder on her than they are on Obama.
Obama fired back at Clinton at a rally on Friday evening in Philadelphia that drew 35,000 people, according to the director of security at the Independence Visitor Center.