You don't have to like me. You don't have to listen to me. You don't have to agree with me. In fact, you are perfectly free to completely ignore me just as I am free to completely ignore you. This is what real freedom means.
Understanding freedom is the first step in defining everything else in life. If a student cannot stand up and walk out on a teacher they disagree with than that student is no longer free. Assignment of penalty to the student's action is not a limitation on that freedom, it simply gives the freedom a price. If the student is willing to meet the price, then they exercise their freedom. All of that changes once the penalty passes the point where it prevents the student from exercising their freedom because the penalty itself destroys freedom. For example, if leaving the classroom means the student is suspended from school and denied access to education, then the penalty has moved into a different level. If the penalty is writing an essay, apologizing to the teacher, or having a demerit placed in their record, then the penalty is suitable for the offense.
Dissent and Treason work similarly. If you stand up and give a speech stating that you or your constituents oppose a certain policy, that is dissent. If you encourage your constituents to take to the streets and destroy the businesses of people who support the policy then it is criminal incitement. If you accept money from some individual or group before giving your speech then it is criminal graft. If the person offering you the money is a foreign government or corporation and you accept it, then you have committed treason.
Individual politicians are not required to agree with every policy, bill, or proposal put forth. That is why we have debates, negotiations, refinement processes, deliberations, and finally, floor votes. However, if an individual politician or their party consistently presses for laws, regulations, and policies that are destructive of the freedoms protected by the Constitution, destructive of the tools necessary for prosperity, or empowering of our nation's enemies, then that is treason.
When Nancy Pelosi gave her 2006 acceptance speech she was practicing dissent. In 2010 when she said, "we have to pass the bill so you can see what's in it", she was practicing treason. Why are they different? Because in 2006 she was still open to debate, still transparent in her policies, and still defending her constituency. In 2010 she refused to be held accountable for the contents of the Affordable Healthcare Act, refused to discuss whether it constituted a new tax on the American people, and when people in her townhall meetings opposed the Affordable Healthcare Act she had them removed from the proceedings under armed guard. That is not dissent because forcibly removing someone who disagrees with you is not freedom. Her actions in 2010 were tyrannical and treasonous.
In 2009, when President Obama shook hands with the Queen of England and then a few days later bowed to the King of Saudi Arabia he was being stupid and undiplomatic. Earlier this year when he told Russian President Dmitry Medvedev "after my election I'll have more flexibility" he was being treasonous because he was promising to compromise the will of the American people and betray their trust. In short: