Compass Union Vote Puts Practice of ‘Unit Packing’ to the Test

A union dispute at a popular Washington, D.C., coffee chain is poised to more clearly define the legal boundary for employers’ ability to influence the pool of employee voters before an election.

The fate of proposed unions at five Compass Coffee shops remains unresolved in the wake of votes cast July 16, with union organizers challenging about 100 ballots they say were cast by illegitimate workers. The union accused Compass of rapidly hiring employees to dilute union support, doubling and in some cases tripling staff size.

And the hires included some perplexing names, including an Uber Technologies Inc. corporate manager ...