He has been around a long time.
In 1980 he was one of the performers at the Long Beach Banjo Fiddle and Guitar Festival, which over the years had feature many up and coming, music 'stars' (Jimmy Buffett, Jon Stewart, Guy Clark, Joe Ely, ) as well as some popular headliners (Bonnie Raitt, Kenny Rogers, Linda Ronstat, John Prine, Doc Watson).
Earl was supposed to be one of the ones on the way up, but he never really gained the notoriety of some of the others (though he did win a grammy).
His early stuff was good, then he went political.
He has a decent radio show on “Outlaw Country” Sunday mornings that is enjoyable when he's not espousing politics. However, I have a personal experience that refutes one of his stories that he tells from time to time. Back in 67’ the Monkees and Jimi Hendrix played a concert in San Antonio. Earle claims he went there as a 12 year old to see Hendrix when Hendrix was a virtual unknown in the US at the time. Hendrix was on stage 30 minutes and the crowd was clamoring for the Monkees because most were there for the Monkees. I believe Earle was there as was I to see the Monkees. Hendrix was horrible because he was disinterested and disrespected.