Sarah, it seems like tonight Sanders is walking a very line between wanting to push Biden to the left and claiming that Biden embraced progressive policies too late, or not fully enough. I can see how it might be a little jarring for someone who has been out on a limb for so long to suddenly have other people start to claim your ideas. But that's also the price of having the ideas you've fought for move into the mainstream, and it feels a bit like Sanders is wrestling with that tonight -- is it good enough for Biden to start to embrace them, or put his own spin on them?