OK so maybe President Obama would like to be dictator, and certainly there are those of his policies that are anathema to large segments of the American population (though, surprisingly, our liberal friends tend to give him a complete pass on civil liberties and drone killings), but ...
Let's not let paranoia creep in here. At least not that far.
H.J. Resolution 15 (which has been introduced by the same Rep. on multiple occasions and ignored each time) cannot authorize three terms for a sitting President, because, ah--that would actually take a constitutional amendment, including passage by the GOP-controlled House, the almost evenly divided Senate, and ratification by three-quarters of the State legislatures, many of whom are, you know, not controlled by Democrats. (Not that I'm saying Democrats would go for this: I think Hillary, Joe Biden, and John Kerry would all think three Obama terms was a bad idea.)
So it does behoove people in Libertarian circles to be a bit more circumspect and vet what they read with some common sense before passing it around.
Meanwhile, if you really want to read a fictionalized account about the time when such a coup was most possible, try finding a copy of Michael Kurland's The Last President. You can get a copy on Amazon for between $0.01 and $561 [I'm not kidding] if so inclined.