The answer is T-Mobile. I searched on Amazon.com for a “T-Mobile Complete SIM Starter Kit” and found one for just five dollars. You can activate the SIM through T-Mobile’s website, but not being sure that I would see an option to port an existing number, I opted to do the activation and port request over the phone.
The phone process was fully automated (I was expecting to eventually speak with a person). The system worked flawlessly, and the port from Republic Wireless worked right away! So, five dollars and a few minutes of going through some automated prompts, I was able to make the port to T-Mobile. I was then able to immediately port from T-Mobile to Cricket.
Now let’s be clear: Cricket not being able to port a Republic Wireless number to their system is inexcusable. They are in violation of FCC regulations by not providing this service for home phone, VOIP, or wireline service (as it’s called by the FCC), but if you’re in a hurry to switch, T-Mobile is the cheapest, easiest, and quickest way to get your number away from Republic and over to Cricket.
The FCC web page below delineates the rules that providers are supposed to follow for number porting. If you’ve experienced this same problem yourself, you’ll see a link on the page to file a complaint electronically.
FCC Guide: Keeping Your Telephone Number When Changing Service Providers