Didn’t find your quote at that link.
https://www.law.cornell.edu/uscode/text/28/636
Doesn’t seem a magistrate has injunctive powers, but there’s a lot of legal wriggle room.
It's from the first paragraph of the Authority section.
...there’s a lot of legal wriggle room.
I think the magistrate judge has whatever powers the circuit court delegates.
These petitioners are clearly sophisticated and I can't believe they would make their plea to a court that couldn't provide relief.