Star Trek

I just read the definition of the word republic, and the definition for republic is human beings that elect leaders to represent them; and I just read the definition of the word democracy, and the definition for democracy is human beings that have a common belief system.  So it stands to reason that Republicans and Democrats would try to kill the President of the Federation because he's not human.  I remember the Star Trek Deep Space Nine episode in United Federation of Planets President Jaresh-Inyo is nearly overthrown in a coup attempt by the human Admiral Leyton.

being Rebuplican or Democrat isn't the same. So look up those definitions and get back to us, just do it on the correct board, not this one.

Well, presumably after the formation of the Federation they updated those difinitions to allow for non-human leaders as well. Otherwise there's no way a non-human could have possible been elected.

As others have said, "Demos" means "The People", as in the citizenry -- not "Human". (Only reason it means only humans in the Athenian system is because only humans -- or male citizens over the age of 30 -- made up the politically able populace.)

Republic == Res Publica (actually one teensy point of correction, it's Latin not Greek) translates as "The Public thing", or "Public matter". Or "Matter of the State", or when combined, simply "The State".

Strictly speaking, in our modern parlance, Republic simply equates to a non-monarchy, where the head of state is an elected and not an hereditary ruler. Jaresh Inyo, as pathetic as he is, fits this category.

Party lines within the American system of politics have warped both of these definitions (Republican and Democrat) to indicated completely different things to their original meaning. Just as with "Liberal" in Australian politics. In New Zealand right now, if you say you are a "Republican", it does not indicate party affiliation, but rather support for the notion of New Zealand becoming a republic. There is also no reason to suppose that the Republican or Democrat parties even exist any more in the Star Trek universe -- and if they do, they are probably entirely different to those parties as we understand them now.

That having been said, your argument:

"Republic means electing leaders, and democracy means having a common belief system...

...Therefore republicans and democrats would kill the Federation president."

is based on an entirely non-sequitur progression of logic. Even if any of these premises were true, (which they aren't) it's basically the equivalent of me saying:

"Penguins are black and white, and albatross eat fish...

...Therefore George W. Bush is a ferret."

Remember also that the Federation Council is a multi-species institution, and therefore a non-human president is unlikely to be unprecedented. Leyton's actions were because Inyo was an ineffectual leader, not because he was an alien.