My first idea involves appealing to Christians through the admonition in the Bible to respect the authorities placed above us. Go ahead and read through the first two things I post, as they are linked together. When you are talking to your fellow brothers and sisters in Christ you can explain it faster. However, for us I want to explain this as clearly as possible.
Submit yourselves for the Lord's sake to every authority instituted among men: whether to the king, as the supreme authority, or to governors, who are sent by him to punish those who do wrong and to commend those who do right. For it is God's will that by doing good you should silence the ignorant talk of foolish men. Live as free men, but do not use your freedom as a cover-up for evil; live as servants of God. Show proper respect to everyone: Love the brotherhood of believers, fear God, honor the king. -1 Peter 2:13-17
The latter part of Article 6 of the Constitution says
This Constitution, and the laws of the United States which shall be made in pursuance thereof; and all treaties made, or which shall be made, under the authority of the United States, shall be the supreme law of the land; and the judges in every state shall be bound thereby, anything in the Constitution or laws of any State to the contrary notwithstanding.
The Senators and Representatives before mentioned, and the members of the several state legislatures, and all executive and judicial officers, both of the United States and of the several states, shall be bound by oath or affirmation, to support this Constitution; but no religious test shall ever be required as a qualification to any office or public trust under the United States.
Now, the Constitution sets itself up as the supreme law of the United States. The Senators and Representatives that we vote for are to support the Constitution as well.
The Biblical passage doesn't exhort us to listen to the President, as a lot of Christians falsely presume. It exhorts us to obey the power placed above us. As the Constitution clearly states IT, not the President or the Congress or the Judiciary is the supreme power. Those powers are given to them by the Constitution, and they are subject to it. Therefore, we must follow the Constitution because it is the authority God has placed over us.
As Christians, how can we support someone (even if he supports things we believe in), if he won't even uphold the oath required to take office?
Not only that, but how can we as Christians knowingly support a war that goes against the authority placed over us? The Constitution obviously does not support the type of war we entered into with Iraq. We as Christians need to seriously rethink the kind of government we want in our lives. Do we want the same old government we've had, or do we want a government that respects the Constitution that we as Christians are required to uphold?