The political reality in ND is that having the (D) is the end of the road for you. Since neither party actually represents a specific policy platform, I guess it's 6 of 1 in an environment like that.
After all, what are modern Republicans even about? Obviously they want to deny global warming, police uteruses, kill queer people, theocratize the government... but what policies do they actually care about that aren't equally present in the Democratic caucus?