The GOP debate was the biggest thing going on TV Tuesday night. It's not clear how big until cable ratings arrive later on Wednesday, but preliminary figures have CNN's telecast pacing ahead of the the most recent two.

On the broadcast networks, that made for heightened competition for the December finale of The Voice — though the NBC singing competition was reasonably steady. Not only did it match its spring cycle's closer, it was off less than half of a ratings point in the key demo from the comparable finale last December.

Fast National returns from Nielsen give The Voice an average 2.9 rating among adults 18-49 and 12.6 million viewers. That easily topped all other broadcast outings of the night, though it will obviously fall short of the debate when cable numbers follow. For The Voice, it marks more year over year drops, but the reality flagship's descent has been a slow one.

Most other networks aired repeats and specials on Tuesday night, though CBS did run originals of its three dramas. And all three — NCIS (2.1 adults), NCIS: New Orleans (1.6 adults), Limitless (1.3 adults) — were all steady with last week.

ABC got into the holiday spirit with specials Shrek the Halls (1.0 adults) and I Want a Dog For Christmas, Charlie Brown (1.0 adults).