I would really like to see some states adopt parliamentary systems (let alone the US as a whole). I think it's a far superior system that provides for both accountability and transparency. Ultimately, the party in power holds full responsibility for the actions during its tenure. A parliamentary majority holds total responsibility for its actions and the opposition party is firmly established and ready to govern should the majority fail. The failure of the current system is that when one party is in power, the opposition is disordered and in disarray and always opposes. A parliamentary opposition has a face and can provide constructive opposition. As for divided government in our current system, both sides will essentially point the finger at the other side, which reduces accountability. Keep in mind that the crux of the parliamentary system is that the executive is ultimately accountable to the legislature. The executive must hold and maintain a majority in the legislature to keep power.
Would you support having a Senate and a weak head of state? In Australia we have a single transferable vote and proportional representation system for Senate elections that allows third party and independent candidates to be more competitive. Often, third parties can hold more power as a minority swing vote on the cross-bench in the Senate than they otherwise would as part of the Government or Opposition.
We also had a referendum in 1999 for Australia to become a republic with the head of state, a President, being elected by a two-thirds majority of Parliament and basically taking on the responsibilities of the
Governor-General, who acts on the advice of the Prime Minister.
And, to add to the debate on republicanism, parliamentary republics exist in many countries. I'd note Israel as a unicameral and Italy as a bicameral parliamentary republic.
Not to mention Germany, South Korea, Afghanistan and Iraq, all countries that the U.S. helped to become (democratic) republics and all of them adopted parliamentary systems.
