Another part of that might be because so much appears to be a done deal. Why talk about same sex marriage when it's a "done deal"? Why talk about health care when it's a "done deal"? Why talk about negotiations with Iran when they are a "done deal"? Except for yet another mass shooting why talk about gun control, it's a "done deal"? What's new to be said on any of these issues? How did immigration and the possible nefarious activities of Planned Parenthood get top billing?
Are they really done though? Is the majority happy with the status of marriage, the price of health care, and the present level of security of their homes and country? The more important question today is whether the majority matters. Does the majority make the law? The important answer to that question is — no it does not.
Laws are made by elected representatives. The legislators have to face realistic limits. The majority might want a new bridge, but if the legislators can't find the money there won't be a new bridge. That's just one kind of limit. There are others. Legislators cannot grant every wish of the majority. Legislators have to make sense among other things, the majority doesn't always make sense. Their idea of marriage doesn't make sense if they think marriage is the same as what same sex couples have.
Seeing that the majority can be wrong, what can possibly be done about it? Wouldn't you need a new and different majority? There are means to prevent the majority from making irresponsible demands. The Constitution can limit the things government can do. It can prevent government involvement in activities not suited to government. It can limit the ways government gets involved in other activities.
If that is clearly not working then legislators have to inform voters of the problem and the necessary changes so that the Constitution does work properly. It might not occur during the election process. It will however proceed as necessary.
An obvious problem not only in the United States but other countries as well is the debt. Voters have repeatedly failed to recognize realistic government spending limits. That means a "balanced budget" or some sort of other limit on debt is required in the Constitution. Such a limit has long been considered a threat to national security since some worldwide crisis might require sudden and vast military spending. There are debt limits in the law presently, but they are meaningless since whenever they are reached they are simply raised. The debt problem is so terrible now that the new question is which threat is the worse, the problem of national security or the problem of the debt? It might well prove that the threat to national security is not the worst of problems.
Another obvious problem is that marriage has become meaningless. It did not happen in one day. The decision in Obergefell v. Hodges last June marked the end of any serious definition of marriage, but it was losing its meaning for decades. Just under fifty years ago "no fault" divorce laws were passed. Over time people have taken their marriage vows less and less seriously. Now they flit in and out of marriage as though it's an airport phone booth when they even bother to marry. The Supreme Court was not totally to blame. Those judges weren't even on the Supreme Court when the problem began It had to rule whether the status of marriage today is significantly different from what same sex couples might have. The institution of marriage needs a major overhaul to be taken more seriously. An amendment similar to those passed by 31 states already is just a part of the solution.
Another part of restoring marriage to significant meaning is opposing the repugnant and immoral practice of abortion on demand. An amendment has long been sought to correct the mistake of the Roe v. Wade decision and to end abortion on demand. There is a problem with the wording. Although it is scientifically obvious that life begins at conception, how should an amendment be worded? If it simply says, "Life begins at conception," what does that mean? Does legal age begin at conception too? A possible practical amendment might say, "A woman who chooses to create a life with a man shall be responsible, with her partner, to support and defend that life from its conception to its maturity." That has been the assumption for centuries and the basis of marriage. It is not a new idea. It was never a bad one, but there should also be included exceptions of a limited and clearly defined type. The option of assigning support and defense by adoption should be one. An exception "for the life of the mother" is vague. It should rather be "unless a clear medical reason can be presented to a court that the mother will not survive the birth of the child." If the reason needs to be put on paper and presented to a court that option will less likely be abused. Notice that if the mother did not choose to create a life, she is not held responsible. It might be necessary to specify that "the manufacturers of birth control methods are not responsible if those methods fail." The people who choose not to abstain will be held responsible.
Considerable confusion over medical responsibilities needs to be resolved elsewhere too. Why do people who paid for Medicare for decades suddenly have to pay $200 per month for insurance? Why haven't costs gone down since the new law was passed? To prevent further irresponsible voter interference with private medical decisions consider an amendment that says, "No medical treatment shall be received by force of law and no payment or payment scheme shall be forced by law for irrevocably declined medical treatments except as necessary to carry out a penalty for a crime." Exceptions for vaccines might be considered, however there really is no political reason that voluntary vaccinations aren't sufficient. People who complain they are "forced" to finance the military have options. They can set limits on taxes as part of the general budget control already mentioned.
The automatic citizenship granted to people born to parents who are in the country illegally has become an encouragement to break one law to take advantage of another. That also needs to be changed.
The campaign season is a time to discover the wishes of the majority. There might not be much discussion of the "done deals" on many of these issues. After the elections reality must be addressed, and if the voters have unrealistic demands those won't be met.
Amending the Constitution is no simple or easy process. In order to correct an irresponsible majority it might be necessary to let them have their way first, let the country crash and burn, and then see what new majority emerges. A reasonable assessment of the current conditions is that a crash and burn is under way.