The real question... some say "lack of likability", others blame the changing demographics (read: Mexicans continue to flood in, legally or not), some blame piles of Dem money and effort. Taking Texas would be a huge win for them.
(On our side, NJ is suddenly in play. It was polling +16% Dem a month ago... but corruption accusations have but that to +2%, and some sitting Dems in NJ openly saying they will not vote for the NJ Dem incumbent Senator Menendez. Would be the first new name Republican Senator elected in NJ since 1959.)
For goodness sake, Cruz betrayed Trump at the convention. Could there be a more effective way to alienate the base? People haven’t forgotten