Ah. Now I understand. This would have been a better way to say it.
Unemployment trended down under Obama from a Recession peak of 10% to about 4.7% when Trump was elected. In nearly three years since Trump was elected, it's gone down about 1%.
Again, it didn't have far to go, which cuts two ways. 1) It would have been hard for it to go much lower under Trump (or any president); and 2) it's not much different than it was when Trump was elected.
The 10% recession peak was still in the first year of Obama's presidency. It was 9% in April of 2009. I'm not sure using 7.8% (from January, 2009) is any kind of fair measure, but it would still have been 3.1% reduction in unemployment, despite having a huge recession in motion.
The link shows the data in its naked glory. If anyone can detect a turnaround in 2017, well then good for them.