So I checked the archives: No Coverage
I checked the Vanderbilt Television News Archives using as keywords the names of the indicted RNC officials and keywords like "new hampshire" and "election" and (indicted or convicted). No stories on ABC, NBC, or CBS at all.
Searching the Washington Post via Lexis/Nexis, I found a total of about five relevant stories over three years, none of which were anywhere near the front page and none of which were longer than a few hundred words.
In short, when Republicans did it, the "liberal mainstream media" ignored it.