In the U.S. both political parties are corrupt. They are both more concerned with gaining and holding on to political power than they are in governing justly and honestly. Both parties rail against budget deficits, when they are out of power. Both parties ignore budget deficits when they are in the ascendancy.
Republicans need theologically conservative Christians to vote for them when at the ballot box, but most elected Republicans seem to loath evangelical Protestants, conservative Roman Catholics and other cultural conservatives after elections are over.
Politicians are, for the most part, parasites in the body politic. We Christians need to be concerned with promoting Christ Kingdom and being good citizens in what ever land we live in. We must "render unto Caesar that which is Caesar's" but we must never believe that Caesar is on our side. Caesar is, at best a VERY fickle friend to the people of God and at worst he is a vicious enemy, but he has no power but that which is granted/allowed him by Christ.