Underrating.
Trump's odds of reelection are going to be 50/50 until at least 2019, because we simply don't have enough information about the 2020 election yet. Anybody who says Trump is a longshot or a no-shot for reelection is underrating his chances, whereas anybody who says Trump is a favorite or a shoo-in for reelection is overrating his chances. Since I've seen much, much more of the former since he took office, I'm going with Option 2.
This, unless something really bad happens between now and 2019