If you're a Christian then you must be a Republican, right?
No. let me offer you a quote from the Evangelical Manifesto…
First, we repudiate two equal and opposite errors into which many Christians have fallen. One error is to privatize faith, applying it to the personal and spiritual realm only. Such dualism falsely divorces the spiritual from the secular and causes faith to lose its integrity.
The other error, made by both the religious left and the religious right, is to politicize faith, using faith to express essentially political points that have lost touch with biblical truth. That way faith loses its independence, Christians become the “useful idiots” for one political party or another, and the Christian faith becomes an ideology. Christian beliefs become the weapons of political factions.
Called to an allegiance higher than party, ideology, economic system, and nationality, we Evangelicals see it our duty to engage with politics, but our equal duty never to be completely equated with any party, partisan ideology, or nationality. The politicization of faith is never a sign of strength but of weakness.
http://www.anevangelicalmanifesto.com/manifesto.php