A constitutional amendment to ban flag desecration fell one vote short of the 67-vote threshold needed for Senate passage and referral to the states.
The proposed amendment, sponsored by Sen. Orrin Hatch, R-Utah, read: "The Congress shall have power to prohibit the physical desecration of the flag of the United States."
The amendment did not seek to ban flag burning. It sought to give Congress the constitutional authority to define flag desecration and ban that behavior in the future. The careful language was an attempt to get around two Supreme Court rulings in 1989 and 1990 that called flag burning and other desecration protected free speech under the First Amendment.
The vote, one week before Independence Day, is the closest backers have ever come to passage. The previous Senate vote, on March 29, 2000, failed on a vote of 63-37. Last year, the House surpassed the two-thirds threshold to pass the amendment 286-130.
With the heat of an election year and the Fourth of July just around the corner, it was a perfect time for lawmakers to debate the amendment.
"It has the support of both sides of the aisle, it has the support in all 50 states, each of those states has called for this amendment," Hatch said.
But opponents, like Sen. Russ Feingold, D-Wis., said the amendment posed a crucial question: "Whether the threat to our country from those who burn the flag is so great, is so great that we must sacrifice the power and the majesty of the First Amendment to the Constitution in order to prosecute them."
Supporters, including many veterans groups, say desecrating or burning the flag isn't free speech, but a grotesque affront to those who fought and died for it.
"I see the flag as something woven with threads and we're each a part of that and I'm a part of that thread by serving my country by serving in Vietnam ... and, to desecrate it, and what so many men and women have fought for is just reprehensible to me," said James Mueller, commander in chief of the Veterans of Foreign Wars.
"Countless men and women have died defending that flag," said Majority Leader Bill Frist, R-Tenn., closing two days of debate. "It is but a small humble act for us to defend it."
But other veterans say they fought to protect the Constitution and the free speech rights it guarantees, which a flag desecration amendment would diminish.
"We just don't say free speech is free and cherished if people who are speaking say things we agree with. We respect the right for people to have opinions about various and frequently very controversial issues," said Gary May, chairman of Veterans Defending the Bill of Rights.
"Our country is unique because our dissidents have a voice," said Sen. Daniel Inouye, D-Hawaii, a World War II veteran who lost an arm in the war and was decorated with the Medal of Honor.
"While I take offense at disrespect to the flag, I nonetheless believe it is my continued duty as a veteran, as an American citizen, and as a United States senator to defend the constitutional right of protesters to use the flag in nonviolent speech," he said.
Some lawmakers tried to short-circuit constitutional debate with a federal law banning the burning of a stolen flag or burning a U.S. flag in order to incite violence or intimidate. That effort failed 36-62.
"I think there is a way to protect that flag without defiling our Constitution. I think there is a way to show our love of that symbol of our great nation not at the expense of that sacred document which has guided us from the beginning," said Sen. Dick Durbin, D-Ill., who sponsored the alternative measure.
Since all 100 senators voted, the Senate will not have an opportunity to re-vote the amendment Thursday, as had been planned. The House, however, did get into the July Fourth spirit Tuesday by passing on a voice vote a measure that would bar condominium and homeowner associations from restricting how the flag can be displayed.
Sponsored by Rep. Roscoe Bartlett, R-Md., the resolution would prohibit those groups from preventing residents from displaying an American flag on their own property. The Senate is considering whether to bring up the measure this year.
FOX News' Major Garrett and The Associated Press contributed to this report.