In February 2021 Texas severely failed to meet power demand in subzero temperatures that lasted around two weeks. Many power stations across the state became inoperable due to these extreme temperatures. Major cities were almost completely blacked out for extended periods. People were burning furniture to stay warm and a good number of people froze to death.

When that happens on the East or West grid, they just grab power from unaffected regions. In Texas all they can do is rolling blackouts. They know this is a vulnerability in their grid because it happened in 2011 as well.

For some reason they won't harden their stations against the cold, but they wouldn't have to if they just got on the East or West grid. So basically they'd rather risk the lives of Texans than either spend the money to harden stations or suck up to the Feds and get on the national grid. Seems pretty stupid to me, but you know a person can be stupid, but it takes a government to be really stupid.