If one thinks it does not matter who is elected president I would advise them to think again.
Historically review events and learn what one man can do to the nation and to the world. He/she (I will use the generic he) can plunge us both into war or he can plunge the nation and the world into a negotiated peace. The latter, of course, is much more difficult. It is easy to drop bombs to resolve disputes as this nation has dropped many of them but it is much harder to pick up the pieces after the bombs have dropped. As Colin Powell famously said of Iraq "If you break it you own it." The president can, through his advisors, negotiate to avoid the possibility of war or even, perish the thought, nuclear war and through his advisors can avoid all the destruction, mayhem and death war inevitably brings but it is the Commander-in-Chief--the President--who will make the final decision since Congress has not done its Constitutional duty in a very long time. War can last, as Iraq II surely shows, and it can last a very long time costing thousands of lives and trillions in treasure.
The profound effect the American presidency has on all of mankind is, in our common era and before, staggering. The selection of a president is serious, perhaps, even the most serious thing one can do in one's lifetime because it is life bestowing and/or it is a life taking choice. It can mean the life and death of you, your children, your grandchildren and beyond. It is why you must make altogether sure that the president selected can calmly and coolly occupy an office not only able to take that 3:00 a.m. phone call but to take all calls in an office that does not lend itself to calmness and serenity. The office of the American presidency has by its very nature life and death global consequences.
Historical examples: Think on World War II. Think on the volcanic destruction of it, the refugees, the death camps, the Hiroshima and Nagasaki nuclear bombs dropped and ask what if FDR had not made the choices he did and Germany won that war? I, a Jew, would not be writing this today. All of Europe and perhaps even you would be marching to totalitarian jackboots. What if a North Korea threatened to drop a nuclear bomb on us today? What would it take for the president to act calmly if such an event threatened? Jack Kennedy during the 1962 Cuban missile crisis knew how close this nation came to nuclear war. It took a man who was willing to act against the advice of his generals to avoid the potential catastrophe. We live today because of the coolness of Jack Kennedy. I can assure you Donald J. Trump is NO Jack Kennedy but the coolness, steadiness and vast foreign policy experience of Hillary Clinton says that she is. War and nuclear war is not a Trump Tower or golf course business deal nor will it conform to the contents of Trump's ghost written book "The Art of the Deal." War and the avoidance of war is serious business for those who are experienced at that business.
Iraq II has been assessed by some foreign policy experts to be the worst foreign policy blunder in US history made by a president "elected" under questionable circumstances who had neither the knowledge nor the savvy and skill to wage such a war after the destruction of the World Trade Center. He waged war, dropped thousands of tonnage of bombs on a nation that did nothing to us, created civil war in that country, created Al Qaeda in Iraq never there before which created its offshoot ISIS. War continues to this day as our 13 year slog is not over yet. Iraq II fractured a Middle East creating never ending civil war and changed the course of global history. It created the Middle East refugees we encounter today and this nation still cannot put Humpty Dumpty back together again if it ever will. The consequences of Iraq have been enormous. We have one candidate, Trump, who is trigger finger happy and wants to shoot from the hip to easily (he thinks) obliterate the problem. That will never happen because our nation is not alone in this fight and has angered many in that Middle East arena causing a cacophony of complexity. This nation will NEVER obliterate the problem certainly not by, god forbid, the naivete of a Trump presidency.
When you vote for president and before you pull the lever for a thin skinned con and bombastic bully that is named Trump choose wisely by choosing the most experienced, the most competent, the most calm and collected person for that office. I believe there can be no doubt your choice should be Hillary Rodham Clinton.
If you think it matters not who one votes into the office of the American presidency think again. The life you save may truly be your own.