Here's what we're following on the shortest day of the year:

Omicron is officially dominant in the U.S.: As depleted hospitals do what they can to prepare for this new surge of COVID-19 cases, President Biden will announce new help for health care facilities and a plan to send a half-billion at-home COVID-19 test kits to people who want them, starting in January.

The politics of Joe Manchin: The Democratic senator, who pulled all support for his party's social spending and climate bill, represents deep-red West Virginia where coal is dominant but in decline. Some point out that the state could benefit from a switch to clean energy.

Winter solstice: Today marks the first day of winter (for the Northern Hemisphere, at least) — meaning things can only get brighter from here.

🎧 Also, on Up First, our daily podcast, the Pentagon is updating its policies on extremism in its ranks.

— The Morning Edition live blog team

(Carol Ritchie, Rachel Treisman, Nell Clark and Chris Hopkins)