We’ve heard this line a lot recently: A company and a union have reached a tentative contract agreement — one that still needs to be voted on by union members. That’s the case for Hollywood actors, Big Three auto workers and some casino workers in Las Vegas. 

But these votes are more than just a rubber stamp.

Rank-and-file union members usually aren’t directly involved in contract negotiations, so a ratification vote is their moment to have a say, said Rebecca Givan, an associate professor at Rutgers’ School of Management and Labor Relations.

“So they’re really trying to assess whether this is the best they could have done or whether it would have been worth their while to stay out on strike longer to get something more,” she said.

Ahead of a vote, many union members will try to get as informed as possible on the contract details — through formal meetings and caucuses organized by union chapters, “and workers will, of course, talk to each other,” she said.

Ideally, they won’t find too many surprises in the contract, added Michael Lotito with the employment law firm Littler.

If they do, “that suggests that there’s a more fundamental communication problem,” he said, “because when you agree to a contract, you’re doing so with the hope — and hopefully confidence — that it’s going to be ratified.”

And if members vote a contract down, he added that union leaders’ jobs may be in jeopardy and employers face fresh threats of another strike.