There is at least one key difference.
When the clerk took the job it wasn’t required she issue same sex marriage licenses. In other words it wasn’t what she signed up for.
When the stewardess took the job, it was an expected part of the job from the start. It is what she signed up for and is now balking after the fact.
Ding, excellent point, my guess is she was an “at will” employee and she was contractually obligated to perform the task, anything else is insubordination and grounds for dismissal. If she had issues about alcohol, she shouldn’t have taken the job, religious or not.
Here’s a clue. Employers have the right to make job changes. Employees can carry out the changes or ge fired. No job must be set in concrete and stay the same as when you hire in or employers would wait 40 years in some cases to name changes.
When a court issues case law the employer must carry it out and the employees follow suit.
There is a second key difference. The clerk was ELECTED, not hired.