Well, I've got a LOT of these. But I guess I'll focus on one.
I wanted to make a roleplay based off of a second American civil war in modern times, and the first roadblock I ran into, of course, was the fact that I wanted the catalyst to be an unpopular policy or president. Because duh. Problem is, you can't have a revolt start for either of those unless you plan to piss half of America off. Trump wins and a civil war happens? GM is a liberal nazi commie. Hillary wins and a civil war happens? GM is a filthy, sexist conservative who wants people to be killed by guns. Bernie wins and a civil war happens? GM is a tinfoil hat-wearing, ancap conspiracy theorist who hates the word "socialism" and will kill anyone who utters it.
Of course, I couldn't make a fictional president either. Because they'd have to have some policy to incite a revolt, which in my mind could be either strict gun laws, racist and xenophobic policies, or being socialist. And all of those have the same problems.
In the end, I decided that it would be easier to have the players be VICTIMS of the war, trying to survive in a bombed-out city so I could at least avoid forcing them into ideological roles. Specifically, the city would have been Durham NC, because I really like Durham NC. If you've ever played This War Of Mine, it would have been like that. Scavenging for materials, running into gangs and criminals, having to make tough decisions between a better chance at survival and clean hands.
But I couldn't manage to come up with a functioning plot, so I scrapped it.
A shame too, because I really love Durham.
I would love to do a TWoM-sytled RP some day. Always wanted to do a settlement-building style RP tho I don't really know how it'd work xD