@gollum,
Actually, that's usually what already happens. Rare are the times when a party has a thorough stranglehold, as reps sometimes do cross party lines for specific votes.
Also - your premise is flawed. What if the minority party is the Nazi party? Further, one thing about majority rule is, it's a lot closer to the will of the people. Flawed as it often is, it's still generally better than thumb on the scale politics, where legislatures attempt to pretend they know better than their constituencies.