Massachusetts was actually the first state to abolish slavery, in 1783. The 1777 Vermont constitution did not free male slaves under 21 or females under 18.
There was a
huge backlash against Vermont's civil unions bill; in the 2000 election very popular, (at the time) moderate Democratic governor Howard Dean beat his John Bircher opponent Ruth Dwyer (among her views, that the South should rise again and Vermont join the CSA) by only 50-37. Republican Senator Jim Jeffords beat his openly-gay, Democratic opponent, State Auditor Ed Flanagan, by nearly 3-1. (Bernie Sanders beat his transgender Republican opponent, Karen Kerin, by more than 3-1, easily his largest ever margin). Republicans took the state house of representatives, and then took the state senate and the governorship as well in 2002.
The political shift in Vermont has quite a bit to do with the fact that well under half the state's population was actually born there, and the newcomers are almost unanimously the birkenstocks crowd.