I think you need to allocate some time towards the end to remove any grammatical mistakes. I will point out the more obvious ones -
"This conclusion is based on that President Leonards actions" - I think you meant "based on the belief that". You need an apostrophe here - "Leonard's".
"Therefore, the conclusion is relies on weak premises" - remove the "is".
"
It could also have been caused by the actions of the previous president, whose effects are delayed." - "whose" refers to the previous President.
"Even though the low approval rate could be caused by actions done by the president, perhaps an increase in minimum wage, which could have reinforced the unemployment rate, it is not at all obvious from the argument." - It is not clear what you are trying to say. Perhaps, you could simplify the sentence.
"
Finally, this argument is flawed for several reasons." - Not clear what you are trying to do here. this sentence seems to imply that several more reasons follow, but then none do.
You can also add more points to your essay argument. You do not need to include all of them. Try to challenge each sentence -
An approval rating below 50% is not necessarily dire. What was the average approval rating of previous presidents? Probably the current President's rating is much higher than the historical average.
Unemployment rate is not the only indicator of economic stagnation. What if his performance on other economic indicators are stellar?
What if international conflicts caused the unemployment rate to be higher than average? Probably companies in conflict zones that outsource jobs shut down
What if the unemployment rate would have much higher than it is now if someone else were the President? He probably brought it down to its current levels. It would have been much higher otherwise.
What if the unemployment rate has reduced from its previous high during the tenure of the previous President? (even though the unemployment rate is higher than its historical average)
What if there are no qualified candidates for the Presidency? What if other candidates make the situation even worse?
Are there are positive signs of improvement in the economy? If there are, then it seems that his policies are working.
What if the Senate and the House are responsible for economic stagnation?
What if recalling the President results in power vacuum and make the situation even worse?