Today, President Biden is poised to deliver what is expected to be a spirited speech at a gathering of the International Association of Fire Fighters, the first major labor organization to endorse his 2020 White House bid. Biden, who has promised to be “the most pro-union president you’ve ever seen,” will be the first sitting president to address the group in more than two decades. While not a campaign event, Biden’s speech should offer a preview of the themes he will press if he moves forward with a 2024 reelection bid.