There are plenty of sons of the devil who categorize the denominational institutions as identical with the Church, then infiltrate those denominations using social tactics, to later propogate human good and evil without any fellowship with God.
They are probably best discerned by understanding spirituality is remaining under the control of the Holy Spirit in one's thinking and then discerning the fruits of those who claim to represent the Church.
I've found many political conservatives have slipped out of fellowship with God, and are scarred by focusing their thinking on human good independent of divine righteousness. A good thing done in a wrong way is still wrong.
I've found those who succomb to Satan's cosmic system mature in unrighteousness beyond mere arrogance and acting independent of God, such as Christian activists and crusaders whom I describe above, and descend lower into what I identify most political liberals of relishing, namely rebellion and attacks upon anything created by God.
Nationality, Family, Marriage, and Volition are all divine institutions. Many conservatives will support those institutions, yet may remain very separate from fellowship with God. They are guilty of moral degeneracy. Many liberals begin and continue to erode those institutions, instead falling into an immoral degeneracy.
I have witnessed many liberals who are immorally degenerate, mature in their degeneracy to the point of becoming artful master liars who gauge their success on how many people they can fool into believing they are sincere, while they intentionally deceive. I have not witnessed many sincere liberals who are in fellowship with God, but who tip their hand of being out of fellowship by many other standards.
For example, any minister who claims to be an official in a church and adamently demands his concurrent 'homosexuality' immediately tips his hand to a lack of fellowship with God.
Thanks for the response. By "theologically conservative but politically liberal" I was thinking more of Jim Wallis or Ron Sider type as American examples - someone who opposes abortion, pornography, gay "marriages", illicit drugs BUT who thinks redistributive taxations, cradle-to-grave welfare state, gun bans, abolition of capital punishment, and spineless pacifism on intl relations are good and mandated by the Bible. Are they real Christians?
I agree that there are also political conservatives who are at worst CINOs but I have seen occasions in the past that people name-call any brothers or sisters in Christ who dared to say Gulf War I was right, welfare reforms should go ahead as "theological liberals/apostates" or "rebelling against God and His Word". It was a confusing world really...