As the delta variant rages on, President Joe Biden says he will issue an executive order that would require certain businesses to mandate the Covid-19 vaccine for their employees.There's a high likelihood this move will spur legal challenges, and it also raises the question of what the federal government can and can't mandate.Biden's executive order could be a unifying force when it comes to the vaccine. It could also deepen the power struggle between federal and state authorities.So, who should have that power? And how does polarization complicate things?Want to support 1A? Give to your local public radio station and subscribe to this podcast. Have questions? Find us on Twitter @1A.