The problem with this theory was that the Sandra Fluke fiasco was purpose-made for politics. Her sole claim to fame was as a "pro-choice" feminist.
The incident with Machado on the other hand was long, long before Trump was running for the Presidential nomination; politics had nothing to do with it, at least until Trump's surrogates decided to put that smear article out a couple days ago. Until then, it could have simply been brushed off as a personal beef and nothing more, but then Trump felt the need to shoot the messenger. Did the Dems capitalize on it? Of course, just as the GOP would love to capitalize on all of Bill Clinton's paramours, willing and unwilling.