It depends how genuinely independent the next president is of the intelligence bureaucracy. This isn't really a partisan issue. The problem the president face

It depends how genuinely independent the next president is of the intelligence bureaucracy. This isn't really a partisan issue. The problem the president faces is that if you piss off the intelligence services, you a.) won't get much useful intelligence to do your job and b.) have powerful organizations with lots of dirt on you who want to see you gone. So from a strict power-play position, it's never wise to piss off the intelligence services. Those who do likely won't find themselves in power for long. (We've seen some of this with Trump, who did piss off the intelligence services and now sees a steady barrage of leaks designed to damage his reputation and undermine his power, as well as administration officials who keep critical information from him because they don't trust him with it. Personality-wise I would've expected Trump to be more likely to pardon Snowden, but Trump is philosophically an authoritarian and not terribly sympathetic to people who undermine authority.) I could see Sanders or Andrew Yang potentially pardoning Snowden, but I think Warren or Biden would be too cooperative with the government bureaucracy.