Could this be the beginning of the end?
As has been demonstrated time and time again, the answer to that question is always "no." People really ought to stop asking it.
National polling trends put "the beginning of Trump's end" back sometime around the start of March. It doesn't really matter how the R nomination contest goes for him if he can't turn that around. (And no, I don't think he can.)
That's the beginning of the organized anti-Trump effort. You really need to start reading these national polls in the context of the current stage of the race (i.e. contested Pub primary), which means that a lot of Pubs are against Trump. They will come home by November, like the PUMAs.
One thing I notice is that many of the women Trump has insulted are REPUBLICAN women. Heidi Cruz. Carly Fiorina. Megyn Kelly. These folks are not folks who generate a lot of sympathy amongst Democratic and liberal women, and Republican women have heard so much against Hillary that they can probably bring themselves to vote for Trump and puke later.