Barr left the Republican party in 2006 over what he called bloated spending and civil liberties intrusions by the Bush administration. He is expected to make an announcement tomorrow at a Libertarian conference in Kansas City.
Should he run, Barr might sap votes from Republican John McCain, but whether it would be enough to alter the outcome of the presidential vote in any state is uncertain.
A national Libertarian Party spokesman says the party is eagerly anticipating Barr's speech, and says it would be "thrilled" to have him run for the nomination.
Among the other Libertarian presidential candidates is Mike Gravel, a former Democratic senator from Alaska.
