The big domestic news today is the Conservative Political Action Committee conference, or CPAC, where dozens of major Republican and conservative thinkers (from Minority Leader John Boehner to Glenn Beck) are speaking to 10,000 members of their base. The big news out of CPAC is the Mount Vernon Statement, a commitment to Constitutional-conservative positions with signatories including Grover Norquist, Edwin Meese, and Tony Perkins.

Here is an excerpt:

Each one of these founding ideas is presently under sustained attack. In recent decades, America's principles have been undermined and redefined in our culture, our universities and our politics. The selfevident truths of 1776 have been supplanted by the notion that no such truths exist. The federal government today ignores the limits of the Constitution, which is increasingly dismissed as obsolete and irrelevant.

Some insist that America must change, cast off the old and put on the new. But where would this lead -- forward or backward, up or down? Isn't this idea of change an empty promise or even a dangerous deception?

The change we urgently need, a change consistent with the American ideal, is not movement away from but toward our founding principles. At this important time, we need a restatement of Constitutional conservatism grounded in the priceless principle of ordered liberty articulated in the Declaration of Independence and the Constitution.

The Mount Vernon Statement draws support from a number of conservatives, including many members of the Tea Party movement. Here's the problem. The Mount Vernon folks espouse sticking to the letter of the Constitution. But many of them also vocally support some things the Constitution does not -- like military commissions for enemy combatants and closed borders.

According to the Constitution, enemy combatants should be tried in civilian courts. And the Declaration of Independence lists the British crown's restriction of free immigration as one of its grievances: "[The king] has endeavoured to prevent the population of these States; for that purpose obstructing the Laws for Naturalization of Foreigners; refusing to pass others to encourage their migrations hither, and raising the conditions of new Appropriations of Lands."

Some Constitutional conservatives -- like Norquist -- do not attempt to square this circle. They instead support free immigration policies and trying terrorists in civilian courts. Others, it seems, reconcile themselves to an elastic constitution in some circumstances. Either way, it is the subject of feisty debate among conservatives.