Employers often have policies that are more favorable to employees than the law requires. For example, from my layperson's understanding, PA law doesn't require breaks at all for employees (except minors). Despite no legal requirement, many employers, likely including yours, provide one or more paid breaks plus an unpaid meal break, if scheduled for at least X number of hours, such as 6 or more.

To digress a bit, lots of issues get discussed during political campaigns, but generally little to nothing regarding worker and consumer protections. Most people assume they have legal rights they don't.

Every state in the U.S. is At-Will (some mention Montana as an exception, but my take is even most jobs there are at-will) unless one has a collective bargaining agreement / contract in place stating otherwise. With that said, larger employers are generally careful when laying off / terminating employees to avoid litigation and paying out unemployment more than they have to.

Now to your question, if it's a big box retail employer, make clear you need to leave at your end time. If pressed, say it's for family, school, etc. No need to go into details beyond that.

Bottom line, if you need to leave on time, leave. Or if it's a day you can extend, stay longer. Retail, if that's the job, is used to dealing with that along with call offs. Don't let managers guilt-trip you.

On a related topic, if the job is of a part-time nature (even if you're getting full-time hours currently), they can and likely will reduce hours after the holidays. If it's retail, Feb-March are the most brutal.

Hope this helps.