In many cases it's a numbers game. Not a bad idea to connect with old colleagues or acquaintances, or to network with current or recent ones.
The unfortunate reality is the job market is kind of awful right now, insofar as the experience is for someone looking, so you run better odds leveraging who you know.
Specialized job boards are particularly great places to target (for example, postings at large public or private institutions nearby instead of generic job boards).