There is belief on both sides of the political aisle that the discourse in this country is more partisan than ever. In fact, many claim that it is downright nasty, with name calling and people shouting down those they disagree with. I am not sure if discourse is any more uncivil today than in the past (I think far too often an ignorance of history makes it appear that we are living in a unique time) but I do think that there should be an open debate about ideas and that people can agree to disagree in a polite way.
That being said, there comes a point when what your opponent says is no longer just their opinion, but instead crosses a line and turns into proposed legislation. Economists can respectfully disagree on the effects of a minimum wage, or taxation, or tariffs/quotas. But disagreeing over dinner is not the same thing as disagreeing over policy that has the force of the government behind it. I will respectfully disagree with economists who claim that a minimum wage does little damage to low skilled workers. But when that same economist takes his or her opinion and tries to make it law I will strongly disagree with them. That is because as an opinion it can cause no damage, but as a law it can cause the exact harm to low skilled workers that I believe it does. In that case I feel that I have a moral obligation to try and prevent that damage from occurring.
To say that each of us should be respectful of different opinions seems to apply when each of our opinions are just that, opinions. Once people try to make their opinions laws, laws that use the government monopoly on legitimate force to be executed, those opinions can actually cause real harm to people. For example, we can agree to disagree with someone who has the opinion that theft is OK, or murder, or rape in so far as they DO NOT ACT ON IT. We can think that they are a terrible person, but we as a society do not throw them in jail for their thoughts, and rightfully so. But as soon as they act on those opinions they have crossed a line and when they do actual harm to others society punishes them accordingly.
Many opinions cause similar harm once they become laws. The opinion that marijuana should be illegal is one thing. I disagree, but people can have that opinion. But taking that opinion and turning it into a law e.g. the drug war causes incredible harm to real life people. It is difficult to respect the laws that have followed from people having that opinion because those laws have led to thousands of deaths and incarcerations, destroying families and entire communities along the way.
As another example, many people do no think that American citizens should be able to burn the American flag. I disagree with them, but we can have different opinions on that topic. But the minute someone who has that opinion seeks to make it illegal to burn a flag it becomes more challenging to simply agree to disagree. While some civility should remain, people who resort to the use of government to sanction their opinion are in a way suppressing the opinion of others in so far as the dissenting opinion can no longer be carried out. Once it becomes illegal to burn a flag it can no longer be done sans punishment.
I think that people should politely agree to disagree and that civil discourse is important for a well functioning society. But when opinions cross the line into legislation there is a gray area as to how those "opinions" ought to be treated. Do they deserve the same tolerance as opinions that do not have government force behind them? Or can they be demonstrated against, shouted down, protested against, etc.? History is full of examples of opinions that became laws and then were eventually repealed after people protested against them. Is it always necessary to wait for an opinion to become a law before it is protested against or shouted down? I am not sure that it is, though that is a difficult issue.