Here is the problem with the Texas Primary numbers, comparing 2014 with 2018 - both non-presidential years.
Compare the Democrat votes 2018 with 2014. The reality is, November is not a lock for Republicans, due to this Democrat increase. If Independent voters vote Democrat this time in November (they tend not to vote in primaries), the outcome is more indefinite.
Democrats 2014 Primary Election 510,009
Democrats 2018 Primary Election 1,037,799
Republicans 2014 Primary Election 1,314,556
Republicans 2018 Primary Election 1,543,674