Dozens of the South’s leading political figures urged President Joe Biden on Monday to select Atlanta as the site of next year’s Democratic National Convention to “send a message to the base of our party that we will never take you for granted.”

More than 60 officials signed a letter saying that picking Atlanta for the prestigious event will “inspire Democrats in other competitive states to run, to organize, to fundraise and to volunteer in what is now truly fertile Democratic territory.”

“Selecting Atlanta will put Republicans on notice, making it abundantly clear to them that they will have to compete and allocate resources across every corner of the map if they want to keep pace with the gains we are making as Democrats,” the letter states.

It’s one of the most assertive moves yet by Atlanta boosters competing with Chicago and New York for the quadrennial event, which is expected to bring 50,000 visitors to the city — and showcase Georgia’s status as one of the nation’s most important political battlegrounds.

The letter was signed by senior elected officials and local leaders that include U.S. Rep. Jim Clyburn of South Carolina, U.S. Sens. Tim Kaine and Mark Warner of Virginia, and former U.S. Sens. Doug Jones, Mary Landrieu, Blanche Lincoln and Mark Pryor.

It also featured many of the biggest names in Georgia Democratic politics, with signatures from the party’s entire congressional delegation, former Gov. Roy Barnes and Atlanta Mayor Andre Dickens.

Among other supporters are Cincinnati Mayor Aftab Pureval and the state party chairs of Alabama, Arkansas, North Carolina, Tennessee and Virginia. Houston Mayor Sylvester Turner, whose city is no longer in the running, also formally endorsed Atlanta.

The spree of supporters was designed as a show of force for Atlanta’s proposal just days ahead of the Democratic National Committee’s winter meetings, which begin Thursday in Philadelphia. Biden and Vice President Kamala Harris are both set to speak at the event Friday.

Atlanta’s bid centers on Georgia’s swing-state politics, with references to Biden’s flip of the state in the 2020 presidential election and the victories by Jon Ossoff and Raphael Warnock in the U.S. Senate runoffs that gave Democrats control of the chamber.

“Democratic turnout in the state of Georgia is the single greatest reason that you and Vice President Harris are in the White House today instead of Donald Trump and it is the single greatest reason why Democrats have maintained a majority in the United States Senate,” states the letter addressed to Biden.