The Associated Press has published an article on how to deal with flight delays and cancellations during the government shutdown
A few takeaways:
--If your flight is canceled by the airline, you are entitled to a full refund for all costs including seats and baggage. You can insist on getting an actual refund and do not have to accept a voucher. Even if the flight is nonrefundable.
--as the shutdown looms longer and longer, expect more and more delays and cancellations;
--unlike in the EU, if you are delayed or rebooked by the airline, they don't have to pay for lodging, food, extra costs. Biden introduced a bill to do this, Trump killed it. The airlines applauded;
--if your flight is canceled, try first to get rebooked online, then the phone. If you are a member of the airline's FF program, call that line. If already at the airport, get online and wait your turn. (I also try calling while watiing in line to see who I can deal with first.)
--treat the people trying to help you with respect. They didn't cancel your flight.