US presidential approval/disapproval rates have been nearly static, statistically speaking, since about August. There was a brief spike in approval in early/mid September, which as since been reversed and this is what giving the appearance of an overall downward (not upward) trend.
Whether this is actually a lowering of overall approval (which as averaged ~41.5% for the year so far and is presently at 41.1%) will need a few more weeks to tell.
Looking at the averages of the last 250 presidential approval polls
Last 25: 41.1% approve/54.4% disapprove
Last 50: 41.3%/54.3%
Last 100: 41.1%/54.6%
Last 150: 40.9%/54.5%
Last 200: 41.1%/54.4%
Last 250: 41.3%/54.5%
What's most interesting is there's been a widening in the gap between results on some of the polls. Some are showing very low approval rates (~36-38%), which haven't really been seen since February, while others are showing high approval rages (~44-51%), which were last seen in mid September.
Rasmussen is a case in point, with net approval swinging from -15 to -3 and then back to -13 in the space of 12 days.
So, it looks like the results are getting more polarised, which makes accurate prediction much more difficult.
