text:  It's a key night to the 2024 presidential election. I'm John Saucy, Fox News, President Biden and former President Trump getting ready to face off in the CNN presidential debate tonight. We have Fox's Bill Malujan reporting from Atlanta. The Trump team is zeroing in on Biden's mental sharpness and reminding voters out there that a vote for Biden, they say, is really a vote for Kamala Harris. Team Biden firing back.