Sen. Joseph R. Biden Jr., D-Del., speaking at the first of several oversight hearings on terrorism legislation, called criticism of the Patriot Act "ill-informed and overblown."
In addition, Sen. Dianne Feinstein, D-Calif., mounted a strong defense of the Patriot Act, saying she believes there is "substantial uncertainty and perhaps some ignorance about what this bill actually does do and how it has been employed."
On the GOP side, Orrin G. Hatch, R-Utah, said terrorism legislation has been misrepresented "by extremists on both ends who seem to be dominating the debate in the media today."
Nearly 200 cities and three states have passed resolutions recently contending that the Patriot Act, which expires next year, tramples on civil liberties.
President Bush and Attorney General John D. Ashcroft have campaigned to preserve the law, which faces reauthorization.