I disagree. Riots and protests every few months, half the country losing its shit. Everyday some messed up thing happens, it was like watching a house burn across the street. I mean, I think it is widely known that policies and actions on one term will usually show fruit in the next term. People start spending and investing money slowly once they see things looking up. Look at bush relaxing as many restrictions as he could and getting rid of taxes as much as he could before the 08 crash. Your second term is when the product of your policies are seen. Their first year is spent getting campain promises done as much as possible and getting used to the job (like any employee it takes 6mo-year to be productivr) and 4th year is election year. So it is usually the second and third year after they appointed all the important officials they do anything which means when things take effect is months or a 1yr+ down the road and then you see whatever metric's graph either start going down or up but it is rare for it to peak immediately, could happen but you really can't take credit for economic stuff at least in the first 2 yrs.

Also, keep in mind that americans take away the president's party's majority in congress mid way in the term usually so republican or democrat it is difficult to get things done in their 3rd and 4th year. So their efforts peak at the end of 2nd year and first half of 3rd year and the fruits of those efforts are seen down the road in their last year or the year or two after their last term.