BURLINGTON, Vt. — One of the four Vermont Democrats seeking the party nomination to run for governor in the fall election isn’t old enough to vote, let alone drive. Ethan Sonneborn, 14, of Bristol, met the requirements to be on the primary ballot and is taking his place with the state’s more age-appropriate candidates on the Tuesday primary ballot, to say nothing of numerous candidate forums and debates. “I think Vermonters should take me seriously because I have practical progressive ideas, and I happen to be 14, not the other way around,” Sonneborn said in a recent televised gubernatorial forum.