In March 2008 , Gravel announced that he had joined the Libertarian Party and would seek its presidential nomination , instead of further pursuing the Democratic nomination . In May 2008 , Gravel finished fourth at the 2008 Libertarian National Convention and ended both his presidential quest and his political career , until his 2020 presidential campaign
2008 Libertarian National Convention
2008 Libertarian National Convention
Mike Gravel 2008 presidential campaign