Consider the extensive quote below.  It is from a Christian nationalist site that tries to clarify and disseminate the Christian Nationalist world view.

If you are interested in more, here is a link to this page so you can see a full statement of what they believe.

The organization is Chalcedon.  The creator is R.J. Rushdoony. 

But now for the quote (emphasis mine): 

Misconception 2: Political Dominion

Because we believe that the Bible should apply to all of life, including the state; and because we believe that the Christian state should enforce Biblical civil law; and finally, because we believe that the responsibility of Christians is to exercise dominion in the earth for God's glory, it is sometimes assumed that we believe that capturing state apparatus and enforcing Biblical law on a pervasively unbelieving populace is one of our hidden objectives. Our critics sometimes imply or state outright that we are engaged in a subtle, covert attempt to capture conservative, right-wing politics in order to gain political power, which we will then use to "spring" Biblical law on our nation. This is flatly false. We do not believe that politics or the state are a chief sphere of dominion.

It is understandable why many people assume that we do hold this position, however. We believe firmly in social change. Liberals believe firmly in social change. Liberals believe that social change is the effect almost exclusively of politics and state coercion. For example, they believe that we can change society by means of state-financed and governed "public education"; health, education, and welfare programs; and speech codes. In other words, they believe, like communists, that man is essentially a plastic being that can be fundamentally reshaped by external means — education, wealth, health, penitentiaries, and so forth. Since no later than the French Revolution, most civil governments in the West have believed that social change occurs by revolution, not by regeneration. When, therefore, liberals (and even some alleged Christians) see us supporting and working toward social change, they presume that we are interested in political power. In simpler words, because they believe in social change exclusively by means of politics, they assume that anyone who supports social change or gets involved in politics is attempting to gain state power in order to further a social agenda.

This is a serious miscalculation. We believe in regeneration , not in revolution. Men are not changed fundamentally by politics, but by the power of God. Men's hearts are changed by regeneration (Jn. 3:3). They are translated from the kingdom of darkness to the kingdom of God's dear Son (Col. 1:13). From that point, they progressively work to reorient their lives and every sphere they touch in terms of God's holy, infallible Word. Long-term, pervasive social change is the result of extensive regeneration and obedience by the people of God. This means, of course, that there can be no Christian society of any significance or longevity unless a large number of its members are Christians.

We do encourage Christian political involvement, but not for the reason that many people suppose. In fact, we believe it is important for Christians to get involved in politics because we do not believe politics is too important. The great problem with modern politics is that it is used as an instrument of social change. We at Chalcedon passionately oppose this. The role of the state is in essence to defend and protect, in the words of the early American Republic, life, liberty, and property. It is to reward the externally obedient by protecting them from the externally disobedient (Rom. 13:1-7). Its role is not to make men virtuous; we have a name for civil governments that attempt to create a virtuous society: totalitarian. Biblically, the role of the state is to suppress external evil: murder, theft, rape, and so forth. Its role is not to redistribute wealth, furnish medical care, or educate its citizens' children.

We do believe that the state one day will be Christian, but this no way implies that the role of the state is to Christianize its citizens. The Christian state is highly decentralized (localized). Our objective, therefore, in supporting Christian political involvement is to scale down the massive state in Western democracies, reducing it to its Biblical limits. We do not believe in political salvation of any kind.

 It IS long, but it outlines my reasons for distrusting the rhetoric of many Christians who might be perfectly wonderful people.  The problem is, that some the ideas and philosophies of people like R.J. Rushdoony have been reduced to memes that are so pervasive in our society, we don't even question them.  They are, pardon the multi-layered pun, "intellectual cuckoo’s eggs".  They are slipped in subtly, and surreptitiously but they are damaging, nonetheless - and many moderate and otherwise well-meaning Christians use them as THEY understand them...not realizing the roots that those memes come from, or where they will ultimately lead.

Additionally, people like R.J. Rushdoony obscure the liberal origins of our country, and behave as though the liberal ideals that endure are recent inventions, perversions of the original purpose of the American experiment.  They want to "turn back the clock" to before the liberal ideas they find so objectionable.  To do that, they would have to hand American Sovereignty back to Britain.

It was liberal thought that allowed us to perform the American Revolution in the first place.  To erase the legacy of liberalism in America would mean to erase the Constitution (written by James Madison; a liberal and a Deist), the Declaration of Independence (Thomas Jefferson; a liberal and a Deist), the Center for Disease Control, the Emergency Broadcast System, the Amber Alert system, the Federal Highway system, Public Education - oh let's just say it, it means going back to the middle ages.

This country was conceived in liberty, and dedicated to the proposition that all men are created equal - liberal ideas; revolutionary ideas, political ideas.  It required the development of a new kind of man - one that would not bow to kings even though God himself was said to support them.  The country was founded by men who dared to re-define God and repudiate all they had been told of Him and what He wanted.  An external change had to be effected through political power, through physical separation from the power of the kings, and a revolution in thought and action.  It created a place for people to replace superstition and cowed obedience with reason, dignity and conscience.

Mr. Rushdoony objects to liberals believing that social change is effected through revolution, political action, education, health care, etc.  But if you read the founding fathers, you will see that all of that is the outgrowth of the liberal thoughts of our founding fathers.  Thomas Jefferson invented the foundation for the modern public education system (others expanded and improved upon it).  Thomas Paine proposed something that looked an awful lot like social security in "Argarian Justice".  Jefferson also strongly advocated the redistribution of wealth to prevent the rise of a monied aristocracy, and he was far from alone.

Mr. Rushdoony's intellectual ancestors burned "witches".  Our intellectual ancestors built a nation.