If checks and balances didn't exist, there would be nothing stopping a group i.e. the president, from making whatever laws they wanted.
In essence, if there are no checks and balances, government is no longer a democracy because nothing prevents the group in power from doing what they want. For example, a president that wasn't checked by the opposition party could pass a law saying that they are legally allowed to be president until they die, and nobody would stop them.
The answer is King Louis XVI!
The Crusades & the Inventing of the printing press. Additionally, the population losses sustained in Europe.
If im correct, it was the roman catholic church
Well, lets see, Abu was the one elected, however there was a dispute because some believed that Ali should have been chosen. All in all though, they accepted Abu as their leader.