It is likely that both of the current candidates a will be a single term president for a number of reasons. Trump is a buffoon and Clinton is corrupt and that is not likely to change. The president that we need to worry about is the next one if Clinton wins.
To expand on this.
There are a number of reasons that it is likely the next president will lose in 2020.
Both candidates have serious character flaws and that is not going to change. ( could be the understatement of the year)
Both candidates will be near 75 years of age in the next election. The challenger is likely to be 20 or 30 years younger. I could care less about age but many voters vote for the younger candidate. Trump and Clinton will look old and tired and the challenger will be young and full of energy.
Its the economy. The economy runs in cycles often regardless of what happens in Washington. I have heard that the economy (can't remember where) falls into recession every 9 years give or take. The last recession was in 2008/2009. This means that the next president will likely have to deal with a recession. It is likely it will not be there fault but they will get the blame and there is little that the government can due to get the economy moving.
Government spending. This is what Obama did to get us out of the last recession. It worked but the economy is far from great and in the process the national debt has increased to nearly 20 trillion. More debt in the last 7+ years than in the first 200+ years. Clinton is likely to go the spending rout but the debt is a big drag on the economy and getting bigger. It is unlikely that another big spending bill will be as effective as the last one and the last one didn't move the needle very much.
Lowering interest rates. The fed. dropped interest rates last time to give a boost to the economy. This is a good way to help a sick economy but will not be available in the near future. Interest rates are just above 0 now. There is no more room to cut rates.
Print more money. This is what banana republics do and the fed did it last time. The fed must have been desperate. We may not get away with it if it is tried again.
Tax cuts. Clinton will not go there and Trump will try. The truth is that with the bottom 50% paying almost no tax and the top 15% paying almost all of the income tax, tax cuts just don't have the power to stimulate the economy like they did in the days of Reagan and Kennedy.
Clinton will have a tougher road to reelection than Trump.
Clinton's big push is the historic nature of her candidacy. She will be if elected be the first female president. Many are voting for her for this reason alone. Next election that argument is gone if she wins. and to make it even more difficult there is a good chance that the GOP will nominate a Hispanic.
History in not on her side. Only once in the last 60+ years have we elected the same party to the presidency three elections in a row. The last time it happened more than three times was Roosevelt/Truman. Those times were special. The voters just are unwilling to give one party that much power and that is a good thing in my opinion but it will make it difficult for Clinton even if she does a good job.
If Trump wins the public lands transfer will need to go through congress. It is unlikely that a Trump win will bring along many senators. (the GOP just has too many seats to defend). I don't think the transfer is high on Trumps agenda and even if it is introduced the Dem's will certainly block it in the senate likely with the help of some moderate Republicans that are feeling the heat.
If Clinton wins the betting is that Dem's take control of the senate or come very close to control. The transfer issue is dead for four years. It is after that is more worrisome. In two years the Dem's will need to defend something like 25 of the 30 senate seats in play. Only once in recent years has the party that controlled presidency not lost senate seats. (Bush 43 and that was only because of 9 eleven) In four of the last six off year elections the party that controlled the presidency has lost big time. If the economy is not better the Dem's will lose a lot of senate seats in 2018, if the economy is worse it is not out of line to think that the Dem's could lose close to half of the twenty five senate seats. If the GOP picks up a few more senate seats in 2020 with a likely presidential win the GOP could very will have the presidency and a filibuster proof majority in the senate. Think of president Ted Cruz and 60 plus senators. If that doesn't keep you up at night nothing will.