OTOH it seems all those immigrants have jobs and unemployment numbers in the US are quite low (below 5%). A well functioning economy needs an unemployment rate of a few percent so aiming for zero isn't realistic and below 5% is almost ideal.
The headline U-3 unemployment rate is misleading as it excludes those who have given up looking for a job, includes part time jobs, etc.
People who are not looking for a job don't need a job so there is no need to include them in an unemployment number. Anyway it doesn't really matter because both graphs show that unemployment rates are very near the numbers from (close) before 2008. Also the way the graphs are formatted makes the difference look huge
The definition of "not looking for a job" is not what you think it means. In the USA, the Federal Government get the numbers submitted by the States and policies varies a bit across States.
In New Jersey (a few years back) you have to show evidence of looking for work.
If you cannot find an opening to apply to, (a) you won't send them (the hiring company) your resume to a non-existing opening, (b) they wont call you in to fill an application to a non-existing opening, and (c) you wont have an interview for a non-existing opening. Missing the three will put you into the "no longer looking" category.
A friend of mine kept sending his resume (to a company without an opening) in anyway. He did that to keep receiving the unemployment insurance benefit. It got to a point when he got a nasty-gram back ("don't bother us, we an't hiring").
Shortly there after,
our State's unemployment office actually had a layoff (of contract employees and temps). Then it was 6 months - after the standard unemployment insurance ran out in 6 months... since you have not worked for so long, you are no longer in the work force, so you don't count as unemployed.
No resume send, didn't fill out a job application, didn't go to a job interview for N weeks, you are "now out of the work force" and not counted. If you have a master degree in Chemical Engineering, and all you can find is (say for example) selling coffee at commuter train station 1 hour a day during morning rush hour, you are now count as employed...
That was a system that could work if jobs are plentiful and there is always a place to interview at. That system doesn't work when no one is hiring. Mathematically, you have just one job is the entire USA and you can have U3 with 0.00% unemployment - after waiting for everyone to become long-term unemployed and they wont show up in the U3. That is why in the last 8 years, the U3 unemployment number keep looking better and better ,while the long-term unemployed keep increasing.