As the race for the Democratic Party nomination tightens, the nation’s largest LGBT civil rights advocacy group and political lobbying organization is putting its hand on the scales.

On Tuesday, the Human Rights Campaign announced its official endorsement of former Secretary of State Hillary Clinton for U.S. President.

“We are proud to endorse Hillary Clinton for president, and believe that she is the champion we can count on in November – and everyday she occupies the Oval Office,” said HRC President Chad Griffin, in a news release.

The Human Rights Campaign claims 1.5 million members and supporters nationwide and is preparing for what Griffin says will be an unprecedented organizational effort to register and mobilize America’s pro-equality majority and elect pro-LGBT candidates up and down the ballot. In key states of Ohio, North Carolina and Florida, HRC notes, the population of LGBT adults is greater than the average margin of victory in the last three Presidential elections.

The Clinton campaign says the candidate will accept HRC’s endorsement on Jan. 24 in Des Moines, Iowa. The endorsement comes at a good time as U.S. Senator Bernie Sanders of Vermont is climbing in the polls. In the latest Des Moines Register/Bloomberg poll of likely Iowa Democratic caucus goers, Clinton holds a 42 to 40 percent lead with Ex-Maryland Governor Martin O’Malley pulling four percent.

On Sunday evening, the trio participated in the last scheduled debate before Iowa’s Feb. 1 caucuses. At the debate, Clinton and Sanders were particularly confrontational on the issue of health care, with Clinton defending the Affordable Care Act and Sanders proposing Medicare for all.

Meanwhile, on the Republican side, front-runner Donald J. Trump continues to mix it up with U.S. Senator Ted Cruz of Texas. At last week’s debate, Cruz attacked the billionaire businessman for his “New York values” which, Cruz claims, includes supporting gay marriage.

Trump quickly returned fire via Twitter, revealing it was Cruz who attended a Manhattan fundraiser at the home of gay real estate developers Mati Weiderpass and Ian Reisner.

In a poll released Monday conducted by the Florida Times-Union, Trump holds a 31 to 19 percent lead over Cruz in the Sunshine State. Former Florida Governor Jeb Bush placed third in the poll with 13 percent followed by U.S. Senator Marco Rubio with 12 percent. Florida’s Presidential preference primary is scheduled for March 15.