Monday night marked the Democrats' most interesting debate to date -- which is to say, the audience fell unconscious about halfway through, as opposed to during the opening statements.

But amid all of the technological hubbub and political jockeying, there was one question that stood out. The questioner was Reverend Reggie Longcrier, pastor of Exodus Mission and Outreach Church in Hickory, North Carolina. "Sen. Edwards said his opposition to gay marriage is influenced by his Southern Baptist background," Longcrier stated. "Most Americans agree it was wrong and unconstitutional to use religion to justify slavery, segregation and denying women the right to vote. So why is it still acceptable to use religion to deny gay Americans their full and equal rights?"

Sen. Edwards first stated that based on his religious principles, he was personally opposed to same-sex marriage. Then, he retreated from his principles: "I think it is absolutely wrong, as president of the United States, for me to have used that faith basis as a basis for denying anybody their rights, and I will not do that when I'm president of the United States."

Edwards was clearly mistaken in his appraisal of the role of religious values in politics. Religion shapes morals; morals shape politics. The Constitution forbids Congress from making any law respecting an establishment of religion. It does not bar politicians or voters from consulting their moral compasses in charting America's course on the big issues of our day.

But Longcrier's question was more telling than Edwards' predictably wrongheaded answer. Longcrier's question is symptomatic of a broader strategy implemented by proponents of "progressive" values: shifting the burden of proof.

In adversarial legal systems, one side always has the burden of proving their case; the other, the lesser burden of defending their case. In American criminal law, for example, prosecutors must prove defendants' guilt beyond a reasonable doubt. Defendants must merely create reasonable doubt to prevail. Prosecutors have the burden of proof; defendants must only defend themselves.

In the realm of politics, the question of burden of proof is a vital one. Whoever has the burden of proof is at a disadvantage. Take, for example, the question of taxation. If proponents of higher taxes have the burden of proof, they must make an especially strong case for raising taxes -- they must overcome the presumptions of economics and history. If proponents of lower taxes have the burden of proof, however, they must make an especially strong showing for capitalism -- they must overcome popular (if misguided) notions about the essential unfairness of pure capitalism. Both FDR and Ronald Reagan were master politicians. It is no wonder FDR shifted the burden of proof to the capitalists, while Reagan shifted the burden of proof to Keynesians.

Forcing political opponents to shoulder the burden of proof, then, is an important strategic tool. It is a tool utilized most expertly by "progressives," who place the burden of proof on proponents of traditional values. Defenders of traditional values, say the progressives, must overcome presumptions regarding fairness and justice. Defending the time-tested wisdom of the ages against an offensive assault by social revolutionaries just won't cut it.

Proponents of same-sex marriage would be hard-pressed to show just why same-sex marriages should be allowed. If they had the burden of proof, they would surely fail. But by shifting the burden of proof to proponents of traditional moral values, same-sex advocates like Longcrier avoid having to make an affirmative case for tearing away tradition. Instead of making that case, same-sex marriage proponents assume that a right to same-sex marriage exists, placing the burden of proof on traditionalists to deny that right.

Forcing tradition to shoulder the burden of proof reverses logic. Tradition is the working wisdom of experience. The new should have to overcome the presumptive efficiency, economy and rightfulness of tradition in order to prevail. Change should always have to prove itself -- after all, change has never been tried.

This is not to say that tradition should always prevail. Sometimes change will meet its burden of proof: anti-slavery advocates, anti-segregation advocates and anti-sexism advocates made their cases strongly and forcefully, overcoming the weak arguments for tradition. But constant social experimentation -- perpetual change justified only by empty assumptions about the infallibility of the New -- discards experience in favor of untested theory.

An immature society asks, "Why shouldn't we?" assuming the past is antiquated. A mature society sees the proven value of the old and the possible value of the new, asking, "Why should we?" Sometimes change should be undertaken; sometimes not. This is only right: Some change is progress, while some change is decay. We can only tell progress from decay by asking change to make its case -- to meet its burden of proof.