Vice President Dick Cheney (search), echoing his boss' defense of the Patriot Act, criticized Democrat John Kerry (search) for expressing doubts about the anti-terrorism law.

"The Patriot Act (search) has been crucial to many of our successes. Yet Senator Kerry has chosen this moment, after these victories, to share his second thoughts on the Patriot Act," Cheney told about 500 supporters Tuesday at a campaign stop.

The four-term Massachusetts senator voted for the law and praised it when it passed. Kerry's campaign has said he wants a new Patriot Act, which is also supported by some Republicans in the Senate, that would fix provisions of the act that lawmakers view as problematic, while keeping parts that help the war on terror.

The Bush-Cheney campaign released an ad last week that claimed Kerry's call for changes in the law amounted to a flip-flop on a national security issue and argued that the Democratic presidential candidate had been pressured by fellow liberals. There is no evidence Kerry changed his views based on outside groups.

Cheney told the crowd the Patriot Act is a "good law" that "has done nothing to diminish our liberty. It has helped us to defend our liberty."

The vice president said the law has helped break up terrorist cells in Oregon, New York, North Carolina and Virginia, and has led to the arrest of 300 people for terrorist-related activities.