NEW: A senior aide to Senator Fetterman tells me he will likely be in inpatient care for clinical depression for "a few weeks." For context, it's not unprecedented: Just last year Sen Ben Ray Lujan was out for a few months following a stroke, Sen Chris Van Hollen out for a few weeks.

Before that - Sen Tim Johnson in 2007 was out for 8 months. Sen Mark Kirk in 2012 was out for a year following a stroke.

Here we go... #PASenateDebate

Moderators introducing the closed captioning system in use tonight. Fetterman out of the gate:

“I’m running to serve Pennsylvania. He’s running to use Pennsylvania.”

Acknowledging his stroke as the "elephant in the room."

"I had a stroke - he’s never let me forget that. It knocked me down, I'm gonna keep getting back up."

NEW: @NBCNews has verified these images of Barnette marching toward the Capitol on Jan 6 alongside member of the Proud Boys who were later arrested and indicted for breaking into the building and attacking officers. 1/4 Her campaign's response:
“Kathy was in DC to support President Trump and demand election accountability.
Any assertion that she participated in or supported the destruction of property is intentionally false.
She has no connection whatsoever to the proud boys." 2/4

THREAD: I just spent 3 days with frontline workers at hospitals in a part of Appalachia where hospitalizations have more than doubled in the last month. But hospital staff say many in their hard-hit communities still don’t believe COVID is real. Misinformation is rampant. One nurse told me stories of otherwise healthy 30 year-olds coming in short of breath and not understanding why. She tries showing them chest x-rays and explaining evidence of the disease, but often they don’t believe they have COVID until they’re in critical condition.