It's a noun. "score" is another unit of measurement, much like "years" -- and "years" is a noun as well.
Answer:
The immigration of foreign citizens is limiting opportunity for native people. People from other countries are taking all of the jobs, and they are willing to work for less pay so they get the job first. This is causing the system for getting admitted into the job market to become increasingly more complicated as a result, because businesses are getting increasingly more picky about who of the common folk are being employed. It has even gotten to the extent that employers are processing resumes through machines in order to look for certain key words in the writing.
Explanation:
