A health scare suffered by Sen. Mitch McConnell (R-Ky.) and a repeated moment of public confusion for Sen. Dianne Feinstein (D-Calif.) have returned the focus to the aging of our political leaders — with none more scrutinized than President Biden. Faiz Shakir, senior adviser to Sen. Bernie Sanders (I-Vt.), joins Chuck to detail the hurdles ahead in Biden's campaign for re-election, from potential challengers to scrutiny over his mental fitness.