these days it seems to be implied, if you speak out against Trump, you are automatically an Obama/HRC fan
Because it's just so easy to do. It takes very little brain-power, doesn't hinder them with any of that pesky independent thinking, frees them from having to be challenged on their beliefs...
No different from the hard-leftists calling the right "fascists." Why debate them on their ideas when you can just put a negative label on them and move on?
Someone thinks Trump did something bad? Call them an 'Obama-lover' and be satisfied at how little effort you had to exert!