Some (gasp) facts might be helpful
Is Bowe Bergdahl a deserter? It's looking very much like "No". After all, the man left his unit and came back twice. Who's to say he wasn't planning on coming back this time? AWOL, sure. but AWOL isn't desertion.
Even if he were, does that actually mean we should not bring him home? Do we decide to, without all the facts being in, separate our POWs into the ones we will bring back and the ones we won't? Do we hand the Taliban (or whover we go to war with next) that weapon to use?
(And one more thing. Andrew Tahmooressi, that Marine reservist in jail in Mexico? His situation is utterly different. He drove across the Mexican border with weapons in his vehicle, breaking several Mexican and at least one US law. He's not a POW. He's charged with civil offenses. Which is not to say that perhaps the State Department ought not to get involved in his case. It's only to say that he's not a bit like Sgt. Bergdahl, and attempts to say he is are disingenuous.)