I get all that, but it's a matter of serving the Party's agenda, rather than the serving the people,
Those are not mutually exclusive. For example, if one party passed a bill to get rid of time changes, and the other party opposed it for some inexplicable reason, that would be good for the party that passed it, but it would also be good for the country.
a polarized country is in the politicians interest, it is not in the interest of the people. The task at hand is for the elected officials to work together to serve the people, polarizing, obstruction, divisiveness are politician tools, but they are a betrayal of the people they are elected to serve.
I agree that polarization and divisiveness are bad. I am not defending those. I am defending obstructionism.
Now, I will be the first to admit that obstructionism sometimes causes polarization and division. However, while those are a consideration, they are far from the only consideration. Let's go back to the legalizing murder example. Now, obstructing the bill to legalize murder might cause division. However, I think we would both agree that the benefits of obstructing that bill far outweigh any potential polarization caused by the obstruction. While this is an extreme case, it demonstrates an important point. Politics is all about tradeoffs. Maybe obstructing Bill X will cause division. However, Bill X might be bad enough to be worth obstructing anyway. That would be a tradeoff that we might be willing to make.
Another consideration is that there are many forms of obstructionism, and they are not all created equal. Consider some mild forms of obstructionism like voting against or filibustering a bill. The only people who will even hear about that going on are people who are already very politically engaged, and thus already very polarized. As a result, voting against a bill or filibustering it will have a negligible impact on polarization, so the benefits of obstructing bad bills by those methods will outweigh the costs every time. Personally, I will defend voting against and filibustering bills as a positive good, regardless of which side does it. I believe that a functioning opposition is a sign of a healthy democracy. *
*Note that I said "a sign" not "proof", and "healthy" not "perfect".
Now consider a more controversial type of obstructionism. Let's use government shutdowns as an example. While most people probably wouldn't notice a short shutdown, they will notice a prolonged shutdown when some services close down and the publicity spikes. That will cause more polarization than the previous methods of obstructionism I mentioned. Consequently, there must be a good justification for doing it. In most cases, there probably won't be such a justification; however, there are times when it might be called for. In my opinion, the shutdowns in the last decade probably did not have sufficient justifications. However, it is possible that, under certain circumstances, it could be justified.
Now, I've rambled on for a while, so I should probably make a point somewhere about now. So here it is:
Obstructionism can cause polarization. However, most forms of obstructionism do not, and thus are anything but "a betrayal of the people they are elected to serve." Rather, in most cases, they are serving the people by preventing what they believe to be bad ideas from becoming law. There are also some kinds of obstructionism that do cause polarization and division. In those cases, we cannot immediately dismiss them as a betrayal. Rather, we must look at the justification for their methods. Maybe their methods are justified, and maybe they aren't. However, even in cases when their methods are not justified, we still cannot immediately dismiss them as a betrayal. Why? Because they are not justified - in our opinion. That doesn't mean our opinion is wrong. However, it does mean that the obstructionist can have a genuine disagreement with our opinion and believe that they are justified. They may be wrong, but it isn't a betrayal. Of course, sometimes it is, but we should not be too hasty to condemn without first considering the other side. After all, hastiness to condemn is rather polarizing and divisive itself.
I apologize for rambling on this long. I find this topic to be very interesting, and I wanted to have a more thorough explanation for my stance. Hopefully I didn't bore you or unintentionally trod on your toes, metaphorically speaking.