Bob Barr Announces Presidential Exploratory Committee

"America today faces a grave moral and leadership crisis, and those of us who care about our country's future can no longer sit on the sidelines and remain neutral," Barr told an audience at the Heartland Libertarian Conference in Kansas City, Mo.

The former Georgia congressman left the GOP in 2006 over what he called bloated spending and civil liberties intrusions by the Bush administration.

Barr, 59, became a darling of conservatives in the 1990s for his persistent attacks on President Clinton. He was among the first to press for impeaching Clinton and helped manage House Republicans' impeachment case before the Senate.

He currently runs a lobbying and public affairs firm with offices in Atlanta and outside Washington.

His clients have included the American Civil Liberties Union and the Marijuana Policy Project, a group pushing Congress to allow medical marijuana use and to cut spending for what it says are failed anti-drug media campaigns aimed at young people. Barr also holds the 21st Century Liberties Chair for Freedom and Privacy at the American Conservative Union Foundation and is a board member of the National Rifle Association.

Even out of office, he has proven to be an effective fundraiser, maintaining a political action committee he formed as a congressman. In the current two-year election cycle, he has raised more than $1.2 million, spending most of it on direct mail. His staff said the mailings are intended to spread his "message of liberty."

The other Libertarian presidential candidates include Mike Gravel, a former senator from Alaska who recently dropped out of the Democratic presidential race.