I don't know, Cruz's Indiana campaign was essentially a single-issue "attack Trump for being pro-trans" campaign and it went absolutely nowhere.
I saw a really good analysis that suggested that Cruz really lost Indiana because he was being way too pious and preachy for the state's tastes. It has deep evangelical roots but it is still fundamentally Midwestern in the sense that show-off-y forms of Christian pageantry past a certain point turn off voters. It may have a lot of Southern transplants (that's why it's the way it is) but it's not Southern.
As an aggregate, it seems to me that both GOP politicians and voters as a whole are oddly less hostile to "T" issues than they were/are "LGB" issues...though not by miraculous amounts.
The lesser degree of hostility is pretty simple. Take away all the politically charged language and simply ask people what they spend more time thinking about: their marriage, or the logistics of public restroom usage. The answer for most is their marriage.
