"There's a strong moral argument in favor of the DNC leaks: the American people ought to know that its political process was corrupted by powerful actors within its own institutions."

Actually, the moral argument would be in favor of both DNC and RNC leaks. Selectively leaking a ton of dirt on one dirty party but not the other is not aiding democracy. Instead, it gives one the moral, high ground immediately. That one might be accused of facilitating the leak but many parties available to scapegoat in day & age where hacks and leaks happen all the time. So, this could be a setback for U.S. "democracy."