Retired Army Gen. Wesley K. Clark said Tuesday he favors amending the Constitution to ban flag-burning.
Lawmakers have debated such an amendment since 1989, when the Supreme Court ruled that destroying the American flag was protected free speech.
In June, the House approved a one-line change to the Constitution: "The Congress shall have power to prohibit the physical desecration of the flag of the United States." The Senate has not passed the measure.
Among Democratic presidential hopefuls in Congress, Sens. John F. Kerry of Massachusetts, Joe Lieberman of Connecticut and John Edwards of North Carolina oppose the amendment. Reps. Richard A. Gephardt of Missouri and Dennis J. Kucinich of Ohio favor it.
Kerry said Tuesday that if he saw somebody burning the flag, "I'd punch them in the mouth ... but the Constitution that I fought for preserves the right of free expression."