My candidate for the presidency is low in the polls and has received only marginal press coverage. He should stand out, to begin with, because since 1991, while serving in the Senate, Joseph Biden has been an adjunct professor of constitutional law at the Wilmington, Del., campus of Widener Law School. Our Constitution is not broken. It is, however, being continually fractured by the Bush administration. Especially important, therefore, is for the next president to deeply understand how we can and must be safe from terrorism while remaining a free people under the rule of law, not according to whoever occupies the White House.

Mr. Biden is that candidate. During a speech last year at the Drake University School of law in Des Moines last spring, Mr. Biden spoke vigorously of how the president's authorization of torture (while mechanically denying it), along with the CIA "renditions" and its secret prisons (emptied temporarily by Mr. Bush), have darkened the way we're seen around the world. Moreover, added Mr. Biden: "According to unclassified reporting on last year's National Intelligence Estimate, the abuses that occurred at these secret prisons and at Abu Ghraib and Guantanamo Bay have stoked the jihad movement," giving aid and comfort to terrorist recruiters.

Mr. Biden also told the law students at Drake University that the administration, in concert with the Republican-controlled Congress in the Military Commissions Act of 2006, had stripped detainees at Guantanamo of habeas corpus, "a judicial safeguard that predates our constitutional democracy." Despite the Supreme Court having three times given the detainees the right to enter our federal courts, this deprivation of habeas rights, Mr. Biden emphasized, has led "nations around the world to view Guantanamo not as a facility necessitated by the war on terrorism but as a symbol of American disregard for the rule of law." In the Senate, while enough Democrats joined with majority Republicans to pass the draconian Military Commissions Act, Mr. Biden voted against it. And he has opposed the attorney general nomination of Michael Mukasey, who believes our current rule of law is insufficient to combat terrorism.

What also impressed me was when the agitprop MoveOn.org ran its notorious New York Times ad smearing Gen. David H. Petraeus as "General Betray Us," Sen. Hillary Rodham Clinton, along with most of the Democratic presidential candidates, avoided criticizing that mudslinging ad. Mr. Biden said: "I don't buy into that. This is an honorable guy. He's telling the truth." Also, Mr. Biden has been specific about how he would actually work with Congress, if elected. In July, he introduced in the Senate Foreign Relations Committee, the "National Security with Justice Act."

None of the other presidential candidates has been so intent on restoring our commitment to our own laws against war crimes and to the international treaties we have signed as Mr. Biden has in this proposed legislation, which includes: "Prohibit (CIA) 'Extraordinary Renditions;' Close Black Sites & Extra-Judicial Prisons; Prohibit the torture or Mistreatment of Detainees in U.S. Custody; Extend Habeas Corpus to Detainees; and Modify the Definition of 'Unlawful Enemy Combatant.' " That last provision (ignored by all the other candidates so far as I'm aware) would, Mr. Biden explains, change the "Military Commission Act's definition of the term to clarify that U.S. citizens or lawfully admitted aliens taken into custody within the territorial jurisdiction of the United States cannot be considered unlawful enemy combatants."

Under this baleful Military Commissions Act now in effect, lawful aliens here, many for decades, can be locked indefinitely into legal black holes as unlawful enemy combatants for "purposely and materially supporting the enemy" vague language to be politically interpreted by the Justice Department. American citizens so designated can get a lawyer after being fully databased.

As I have previously noted, Justice Louis Brandeis said, "Courage is the secret of liberty." Mr. Biden has the constitutional knowledge and courage to both keep our liberties intact while acting within our laws to combat our terrorist enemies. Although the odds are very long, it's not too late to have the Liberty Bell ring again on Election Day for this professor of constitutional law, who is a forceful spokesman on why we are Americans. And in the crucial field of foreign policy, Joseph Biden's hands-on experience is far beyond his competitors on both sides.