[rustbucket]

And if the founders had realized that the Constitution needed to be interpreted in light of the founders intention then isn't the fact that a majority of the court needs to agree on that interpretation a valid safeguard?

It may help, but the Court can and does make decisions along purely political/ideological lines rather than what the founders intended.

[Non-Sequitur]

It may help, but the Court can and does make decisions along purely political/ideological lines rather than what the founders intended.

True. But what alternative is there that wouldn't be even more inclined to make those decisions based on purely political/ideological/regional/social lines? Any system dependent on people will have it's flaws and abuses. The idea is to minimize those as much as possible.