Why electors in the electoral college should support the GOP nominee regardless of the popular vote

On December 12, 2000 our republic was kept secure by the supreme court siding with George W. Bush in the Bush VS. Gore decision. Regardless of who you voted for in 2000, Bush won from a constitutional standpoint. Though people are guaranteed the right to vote, the electoral college is what helps elect a President. One of the main factors for establishing an electoral college is to safeguard the republic by preventing people who are unfit for the presidency to lead. Whether or not you disagree with a candidate's position on issue is not relevant to their ability to lead. What is relevant is, are they a danger to the republic, and do they respect the republic and the constitution? By this standard, even a radical left-winger like Al Gore is able to lead, though people like me feel he would not have made a good President. Regardless, the electoral college went to George W. Bush, as did the election. However, there have been times when Presidents who were proven unfit to lead not from a policy standpoint, but from a constitutional standpoint. In 2012, it is my belief that electors should not vote for Barack Obama regardless of if he wins the popular vote or not. Obama is a citizen, but the health insurance reform bill he passed is unconstitutional, but the administration has pushed an illegal mandate on the American public. This is the most visible abuse of power the President has displayed, but there are others as well. Should President Obama be impeached? Certainly, the health insurance reform bill is enough to impeach him. However, with democrats in control of the U.S. Senate, impeachment won't occur. A supreme court trial about the healthcare bill will deal with the policy that led to a departure from constitutional law, but it would not deal with electoral matters in this regard. Therefore, it is my belief that electors should support the GOP nominee even if they popular vote goes to Obama in order to do what the founders want electors to do, safeguard the presidency from someone who is unfit to lead, and in this case the reason that person is unfit to lead is because he has passed a law through congress that is unconstitutional.