He encouraged the 3,500 Democratic activists at a Des Moines fundraiser to create change in the upcoming November elections.
"I have never seen the American people so serious," Clinton told a raucous crowd of 3,500 Democratic activists. "I think I know why. People know things are out of whack. The rhythm of our public life and our common life in America has been disturbed."
The former president was the keynote speaker at the Jefferson-Jackson Day dinner, the Iowa Democratic Party's biggest annual fundraising event.
His appearance sparked interest because of speculation that wife New York Sen. Hillary Rodham Clinton may seek the Democratic presidential nomination in 2008. She has not been in Iowa during this election cycle, though others have already begun campaigning in the state that opens the presidential nominating season in 2008.
Clinton urged activists to ignore that speculation and focus on the midterm election.
"People are sick of partisanship, they are sick of gridlock and they are coming to us in droves," said Clinton. "People know something is wrong and they want to change."
Clinton took sharp aim at the Bush administration and Republicans who run Congress. He called the government "unprecedentedly unaccountable" and criticized tax cuts for the rich, saying they have led to huge deficits.
He also blasted the Republican Party as being controlled by "the most ideological, the most right wing, the most extreme sliver of the Republican Party."
"In Iraq, which is famous for no-bid contracts, $9 billion has gone missing and there has been no serious congressional investigation," said Clinton. "There's never been a more secretive unaccountable administration."