In Defense of Trump (?)

Lots of people, including my favorite blogger Kevin Drum, poke fun at our president for tweeting about his 50 percent favorable rating in the Rasmussen poll.  I'd like to defend him a bit: part of the reason Rasmussen is an outlier apparently is the different universe it's polling.  Rather than "all voters" or "registered voters" which other pollsters seem to be using, Rasmussen is using "likely voters". I'm guessing they are basing their judgments as to whether a respondent is likely to vote based on whether the person voted in 2016.  In addition, they've tended to have a pro-Republican "house" effect.  So the bottom line is Rasmussen is saying that Trump's voters still believe in him, which isn't exactly news.  The other pollsters are saying that the Clinton voters and non-voters are more and more turning against Trump, which also isn't news.