[krapp]

>You realize that the check and balances never required that different parties head each branch of government?

They do in effect, because the existence of political parties means there is no reason for members of the same party to check and balance each other across different branches, as opposed to collaborating across branches to consolidate their power.

Which is exactly what's happening.

[refurb]

No, the checks and balances are defined as simply different people, not different parties.

The Democratic and Republican parties are not monolithic. They don't always agree and there are plenty of differences across individuals.

Hence, the Founding Fathers never required that a different party sit in the executive and legislative functions.