centrist:
(also ‘moderationist’; plural: ‘centrists‘)

Segolene Royal, Centrist politician, France
a person who opposes the ideologies of extreme right wing or left wing political parties;
a person who takes a moderate (not very strong or not very light) stance (position) in political thinking;
a person who is not liberal, i.e. not very free, and not conservative, i.e. not very strict, in accepting policies, ideologies, etc. of a political system,

Robert L. Eherich Jr., Centrist, USA
At one time or the other a centrist must choose left side or right side because not all political issues can be solved by being in the middle or moderate.
Our party is a centrist party with more number of centrists expressing their centrist views on the domestic and foreign policies.
