The United States of America is a Republic, or more accurately, a Constitutional Republic, but nothing like a Democracy (as was the early government of ancient Greece before the advent of Alexander the Great). This political-philosophical idea was given birth near the close of the Grecian Empire millennia ago and quickly adapted by the burgeoning Roman Empire in its early formative years before any such concept of a one-man rule by what would hundreds of years later be called Caesarean Rule. Under a pure Republic all matters of governance are made public matters open for discussion and review by the general populace whom then relay their ideas, grievance's, praises and demands to their district's duly elected official - known as The Senate in Roman times. Members of the Senate would then bring these issues to the floor before the president of the Senate and laws would be made based on majority vote concerning those issues important to the citizens of Rome. Private matters were dealt with by committees formed by the Senate and led by differing member Senators. Affairs that affected all districts within the Empire were handled in these committees and once a plan (draft of a prospective law) was developed within the committee, the president of the Senate would bring it to the floor for general vote by all Senators. Each would vote according to the dictates of the desires of those citizen living with their particular city or state.
From such a concept was The United States of America forged. In our Republic it is the function and constitutional duty of a duly elected official to try and counteract, change or repeal any laws, ideas and arguments that come from the opposing side if they do not coincide with those desires and ideas of the citizens that elected them in their district and State. This has been going on since day one of the Republic. Therefore, to answer the question of this concerned citizen's inquiry - are Republican's being treasonous? - the answer is a simple no. They are, in fact, doing what their constituents demand of them and what is also demanded of them by constitutional law. Back when the founders were putting together this Constitutional Republic there would be literal knock-down drag out fights and even a few duels between members of opposing sides of an issue, law or idea. In the 21st Century we have become a bit more civilized and just go on the internet, television or a radio radio talk show now and lambast the opposition...., or we elect strong opposition leaders as has been done recently to the consternation of the other side.
The feeling from the citizens that voted these members of Congress into office in 2008, 2010 and again especially in 2012 was that their duly elected president and his executive branch administration have finally gone too far in running rough-shod over the constitutional process and well defined constitutionally mandated separation of powers. While this erosion has been going on for several decades since the end of WWII under presidential administrations on both sides of the political aisle, many citizens of America under this president's wanton use of Executive Orders, handing over of more and more congressional responsibility and power to unelected department heads, presidential appointed czars and his self-imposed changing of laws (something reserved only for the Congress) that the erosion needs to come to an end now before there is no longer any Republic left; but, what will remain is a new rule of governance similar to the fate of Rome when it gave up its Republic for the rule of one man over all - Caesar. Many do not want this for the only light left shining on the hill.