This tool maintained by Laura Baker.
Tips:
after:[year] to search reports written after a certain date
example: immigration after:2018
"Think tanks" are organizations that research and generate ideas about public policy. They publish their research--and their opinions--to inform and to shape public debate and influence lawmakers.
Although think tanks can have legitimate sounding names, it is important to evaluate any you are not familiar with to determine any political bias or conflicts of interests.