Plagiarism? Well it's not unheard of in politics....
I haven't looked over all of that highly informative meme, but I know I was disappointed in Biden, who I otherwise like. I don't know how that would play on my mind were he to have run for pres.
Some of what people think might be plagiarism has simply become part of the vernacular (It was a dark and stormy night) or is actually honoring the original writer. For instance, how many other songs refer back to Major Tom without overtly crediting Bowie yet honoring the author without ripping off authorship.
In the many cases where you plagiarize, it is absolute thievery so your commenting by meme on the supposed plagiarism of others by no means alleviates you of your own trespasses.
To one you show which I did randomly bother to google, here's what I found:
http://www.snopes.com/michelle-obama-copied-her-2008-dnc-speech-from-saul-alinsky/After Melania Trump was accused of plagiarizing Michelle Obama's 2008 DNC speech at the 2016 RNC, several sites claimed the FLOTUS herself has plagiarized Saul Alinsky...
WHAT'S TRUE: A portion of a single sentence from Michelle Obama's 2008 DNC speech bore resemblance to a single line from Saul Alinsky's book "Rules for Radicals."
WHAT'S FALSE: Substantial portions of Michelle Obama's 2008 DNC speech echoed concepts and phrasing taken from "Rules for Radicals."
And it's not just a matter of how much content was taken, but also the context used. For instance, sometimes you just copy paste from others into your own sentence or paragraph where it doesn't even follow what other thoughts you might have had. So in that you not only--even if not your intent--try to make yourself look smarter with words that are not yours, when instead it comes out as disjointed, particularly when you've used someone else's words wrongly, when they don't even really apply.
Also with regard to context, there's a big difference between, say someone turning a phrase used by someone else and applying it aptly to a new situation or circumstance and someone misappropriating and misapplying while failing to credit. Also there would be a difference between, say, Michelle using the studied words of someone she might admire and the Lady is a Trump using the words of someone who she'd never invite over for dinner. You see the subtle difference?
One's borrowing. The other is stealing.