Depends. If they intend to use politics to overthrow the Constitution, yes. As we've seen in Afghanistan in the last week, democratic government isn't always consistent with civil liberties.
So, was America a theocracy for the two centuries of its constitutional existence because almost all political officials have been believing Christians?
At some points, in some parts of America, yes.
Do you believe that Christians should somehow be excluded from the judiciary by religious tests such as that proposed by Senator Schumer (i.e., one who has "deep personal beliefs" that abortion is immoral should on that basis be excluded from the judiciary)?
As you are well aware, I hope, religious tests for public office are unconstitutional.
In any event, please cite one major traditional Christian public speaker who remotely says anything about overthrowing our constitutional system and imposing a theocracy.
Gary deMar.
Please cite one scintilla of evidence that Christian believers in this country want to outlaw the practice of other religions or no religions or "impose" their beliefs on others the way the mullahcracy in Iran does or that of the Taliban did.
http://en.wikipedia.org/wiki/Christian_Reconstructionism
And why is it that it is perfectly fine when liberals use the government to impose their moral beliefs on the rest of society, e.g., on sexual activity through public school indoctrination and government promotion of homosexual activity through civil same sex "marriage"?
While I don't agree with same sex marriage, it sure isn't an imposition of moral beliefs on the rest of society. No one is forcing anyone to marry anyone of the same sex, as far as I know. It's very different from, say, executing homosexuals, adulterers, and disobedient children, as the CRs want to do.
I've never heard of the people you mention, and I very much doubt they are at all representative of the vast majority of traditional Christian believers in this country, who I believe support our democratic Constitution and liberties. Like so many anti-religious zealots in this country, you want to discredit Christians in general because of the voice of a few crazies. And there has never been a theocracy anywhere in the US in the history of our Constitution, despite the fact that most people in office and out in our history actually held the religious beliefs that you think are so threatening to American liberties. I just think the whole current attempt to demonize traditionial Christian believers is unwarranted hatemongering and if anything, directly contrary to our history of religious tolerance and liberty of conscience and respect for the rights of others to hold different opinions that is at the core of our Constitutional system. I believe it is the religion-haters who are far more intolerant of religious persons than the reverse in this present day and age.