As a new book about former President Joe Biden’s cognitive health steamrolls its way through the Washington conversation, a new litmus test is emerging for Democrats with national ambitions: Did Biden, in fact, decline in mental acuity while in office?  National politics correspondent and contributing Playbook author Adam Wren joins Playbook deputy editor Zack Stanton to talk it through. Plus, President Donald Trump wraps up his Middle East trip, and the GOP mega-bill is teetering as hard-line conservatives force Speaker Mike Johnson to entertain major changes to the legislative package.