Checks and balances only mean anything when you have ideological differences within the various branches of government, ergo it doesn't mean jack shit when you have 1 political party dominating all branches of government as they are all mostly united in advancing their party's agenda.

It is semi-comparable to the rise of Nazi power in Germany, as the entire government then was seated by the Nazi party (although their government wasn't as seperated as ours is), so it's not directly applicable, although the similarities exist.

Amusingly enough, they also started a war by invading a sovereign nation, we just use yellow ribbons instead of swastikas.