A ping-pong ball may have bounced in Republicans’ favor as a GOP-dominated court was selected at random to consider the fate of President Joe Biden’s mandate that larger employers require workers to be vaccinated. Republican-led states, businesses and conservative groups are challenging the rule, saying it’s not the role of the federal government to decide on workplace vaccines. Unions are also going to court to say the rule doesn’t go far enough. The challenges were combined Tuesday under the Cincinnati-based U.S. 6th Circuit Court of Appeals. The divisions between the courts in play are stark based on whether a majority of judges were nominated by Republican or Democratic presidents.