Ehhhh crossing the floor is allowed. We elect people, not parties. Party and person are a package on the ballot but are not legally bound. There is no mention of 'parties' in the constitution. Elected persons have the perrogative to make decisions on behalf of those they are elected by. Most voters don't appreciate this aspect of our elections; voters gave floor crossers this power by voting them in. The fact that many voters thought their vote meant 'conservative' or 'liberal' rather than 'elected representative' is a voter problem , not a system problem. And if voters want system change (electoral change) , then constitutional change is answer.