IANALE-either but from my understanding the Pardon is so wide (only restriction being preventing from stopping an impeachment) that the President can and has Pardoned people preemptively. There are some other limits on it as well for practical uses.

Most notably, President Ford pardoned President Nixon for basically anything he might have done as opposed to specific charges.

Slate Article on the Subject: http://www.slate.com/articles/news_and_politics/explainer/20...

Obama just gave an interview in Germany where he argued that he can't pardon Snowden.

Interview: http://www.spiegel.de/international/world/spiegel-interview-...

That's baffling. It's happened before multiple times, and Obama really should know that. Anyone have a conjecture as to what's going on there? Does he in fact not know? Is he somehow confused? Is he just lying? Were the previous examples secretly invalid? Is there a meaningful distinction between this case and those?

> Pardoned people preemptively.

Preemptive of any investigation/indictment/etc. Not, as I understand it, in advance of the illegal action itself. (Not a distinction relevant here, of course, just clarifying)

Not true. As others have pointed out, Ford gave Nixon a blanket pardon for things he hadn't been charged with.

The only constitutional restrictions on presidential pardon are

1) He can only pardon crimes against the federal government. That means a presidential pardon won't get you out of a state rap, and it also means he can't use the pardon to affect civil cases.

2) His pardons can't affect impeachment cases. Most notably, he can't pardon himself to avoid impeachment.

Most legal scholars say the president also probably couldn't get away with issuing pardons for acts that haven't occurred yet, since that amounts to a change in the law and encroaches on Congress's powers.

The President's power to pardon is almost unlimited. Anyone may be given "a full, free, and absolute pardon for crimes he has committed or may have committed". c.f. Ford/Nixon