Many questions here belong there but there is no way as yet for flagging them for migration.
Law.SE is a beta site, and as such isn't available as a target for migration. Moderators can migrate, of course, but it can't be a target in the Off Topic close reasons until/unless Law graduates.
It's quite unclear how close Law would be to graduating, even if they do approve the new half-graduation (where they graduate 'ready' sites without waiting for a design, which would include permitting them to be a migration target); they've not even been in beta 90 days, and most graduated sites are in beta for years. Their statistics aren't bad, but they're not stellar enough to suggest they'd graduate substantially ahead of the norm.
What that does mean, though, is you can begin compiling statistics now as to how many questions would be migrate-worthy (ie, how many you'd vote to migrate if it were in the offtopic list), and how many migrated (by moderators) questions are both a) approved by the Law.SE community (ie, not rejected) and b) become good Law questions (ie, get upvotes and good answers). That way, when Law does graduate, you've got the statistics ready to make the argument.