WATCH: The Real Context of That Log Cabin Attack on Clinton's LGBT Record

A video posted Saturday by Log Cabin Republicans attacks Hillary Clinton as doing too little, too late to fight for marriage equality.

But the main moment of the video -- when Clinton is seen on the Senate floor and seems to be adamantly opposing same-sex marriage -- is actually from a more than 10-minute speech in 2004 as she opposes a Republican plan to amend the Constitution and ban gays and lesbians from marrying.

Log Cabin calls out one portion when Clinton, who did not support marriage equality until 2013, said "I believe that marriage is not just a bond, but a sacred bond, between a man and a woman."

The group's president, Gregory Angelo, characterized the speech as one example of Clinton setting back LGBT rights.

"Not everyone in the United States Senate supported marriage equality in 2004, but few took to the floor of the chamber to hammer home the point the way Hillary Clinton did," he said in a statement.

But Clinton took to the Senate floor in July 2004, one day before the Senate was to vote on a federal marriage amendment, and forcefully argued against a marriage ban.

"Is it really marriage that we're protecting here? I believe that marriage should be protected. I believe that marriage is essential, but I don't for the life of me understand how amending the Constitution of the United States with respect to same-gender marriages really gets to the root of the problem of marriage in America," said Clinton, after calling out the growing divorce rate.

Clinton's point was that opposing a ban doesn't mean she's less committed to the "traditional" role of marriage, but she called on Republicans to take more care in considering any amendment to the Constitution, which she called "one of the greatest documents in the history of humanity."

She implored them to spend more time finding ways to combat al Qaeda, especially since everyone knew the marriage amendment lacked enough votes to pass.

Still, Angelo and the Log Cabin Republicans are picking at a problem some LGBT voters have articulated when deciding between Clinton and Bernie Sanders, the Vermont senator who is surging in Iowa and New Hampshire polls. He supported marriage equality long before Clinton, and even before Barack Obama. And Sanders voted against the Defense of Marriage Act that Clinton supported and touted even in 2004 as reason a constitutional amendment wouldn't be needed.

Clinton was met by backlash from activists last year when she suggested that her husband had signed the law in 1996 only as a way to stave off a constitutional amendment. Activists called that revisionist history, saying there was no prospect of such an amendment in the '90s, and that Bill Clinton was actually more interested in winning reelection.

Nevertheless, the Human Rights Campaign endorsed Clinton this month, lending her the support of the largest LGBT rights lobbying group. HRC had actually marked Sanders slightly higher than Clinton on its congressional scorecard when both were in the Senate, with Sanders winning a perfect score.

"Democrats and members of the LGBT community have given Hillary Clinton a pass on past transgressions and even allowed her to rewrite the history of the gay rights movement; Log Cabin Republicans will not," said Angelo.

"It's time for the people of Iowa -- and the country -- to know that when it mattered, Hillary Clinton was wrong on gay rights," he said.

Watch the Log Cabin attack video below, followed by Clinton's complete floor speech from 2004: