The staying power of Mr. Trump's supporters says as much about them as it does about Mr. Trump's questionable performance to this point. I would have thought that a great many anti-Clinton, anti-Democratic Party, pro-Bernie Sanders voters-for-Trump would be be scaling back their expectations by now. That doesn't seem to be the case unless the 8% undecided (from the article) all threaten to turn against the Republican Party in the 2018 mid-term elections, Mr. Trump appears to be in a secure position with regard to Congressional support.