Despite being known for its strives in independent leaders, like Angus King, Mainers have held stead fast in their republican and democrat labels. Maine has showed a .8% decrease in registered republicans (down to 28%) since 1996, and a .4% increase in registered democrats (from 31.7 to 32.1), the number of registered independent voters in main has only increased 0.1%.
Check out the Chart here.