The Democratic Party has (recently) come to value unity and party discipline (A.K.A. loyalty). The Republicans have lost unity and discipline over the past 10+

The Democratic Party has (recently) come to value unity and party discipline (A.K.A. loyalty). The Republicans have lost unity and discipline over the past 10+ years. You can see this from how Democratic Party leaders critize their counterparts for failing to keep members 'in line', whereas the opposite (Rs criticizing Ds for lack of discipline) is rarely the case. This treatment of non-establishment (or non-conformist) politicians (Sanders being one case) is just a symptom of this medium-term trend.