If you are partisan to the Democratic Party you:

a. dislike them

c. support them

b. work against them

d. belong to the Republican party

If you are partisan to the Democratic Party you:

C. Support them

Lets look up the definition of 'partisan' to find what this may mean,

Partisan means to be a strong supporter of something, and this sentence says the Democratic party, so that means they support them.

Answer would be ⇒ support them