KANSAS CITY, Mo. — Former Georgia Congressman Bob Barr eased into presidential politics Saturday with an announcement that he has formed an exploratory committee to gauge voter interest in his candidacy as Libertarian.

If there are "sufficient numbers" of people behind a Bob Barr presidential race, he's running, the former Republican said.

His announcement brought whoops and applause from the audience of 130 Libertarians, mostly from Midwestern states.

"We are at a tipping point," Barr said, "in terms of the willingness of voters, in significant numbers, to consider alternatives to the major [political] parties."

Barr conceded it was unlikely he could win, but he said his potential candidacy would be an opportunity to preach the Libertarian philosophy.

"I don't think any past performance by a Libertarian candidate is any benchmark," he said. "Are my expectations that the Libertarian candidate will win [the White House]? No. But with a credible candidate, anything is possible."

He added that the Libertarian Party "has been presenting itself as much more mainstream" as voter dissatisfaction increases with the decisions of Republican and Democrat officeholders.

In 2003, Barr left politics — he had represented a Cobb County-centered district since 1995 — to return to practicing law, offering media commentary, consulting and teaching. He is a regular columnist for The Atlanta-Journal Constitution.

In recent months, he has been a frequent speaker at state Libertarian Party conventions and conferences like Saturday's Heartland Libertarian Conference. Next week, he has scheduled time with radio talk shows and television personalities, to be followed by more Libertarian conventions.

Barr, once a federal prosecutor in Atlanta, came to a hotel in the middle of an office and industrial park on the outskirts of Kansas City to announce his intentions.

He is the second former member of Congress to flirt with a run for president as a Libertarian. Former Alaska senator and one-time Democratic presidential candidate Mike Gravel switched to the Libertarian Party last month.

"I'm excited to see what he [Barr] has to say," said Doug Burlison, a Libertarian who serves on the Springfield, Mo., City Council. "And I'm excited to see what Mike Gravel has to say. It's exciting to have to former office-holders running [as Libertarians]."

At the Kansas City conference, Barr, 59, repeated his message of less government and protection of civil liberties.

His themes, some say, will appeal to supporters of Rep. Ron Paul of Texas, a GOP presidential contender who remains in the race even though Arizona Sen. John McCain has accumulated the delegate commitments to win the Republican nomination this summer.

Eight men and two women, plus someone identified as "none of the candidates" and another as "future/unannounced candidate," have raised money as Libertarian contenders for president. The nominee will be picked in late May at the Libertarians' national convention in Denver.

Barr, who as a Republican congressman helped impeach President Bill Clinton, focused many of his complaints on the Republicans he once supported.

"The American people are much more sensitive to big government and the problems of big government," Barr said. "Republicans in Washington have opened people's eyes. Both major parties are big-government parties."

"The two-party system is the problem. If we continue to rely on the two-party system, then shame on us."