I came to this country 11 years ago with a J-1 visa and a PhD in STEM. Never skipped paying the taxes during my J-1 to H-1, to Green card to US citizenship. Never complained about the process, waited patiently in line, paid all fees (including lawyers'), took all the required tests, and am very happy to be a US citizen. From day one I entered in this country I have been taxed - paid for Medicare/ Medicaid/ Social Security/ County/ State/ Fed - you name it.
For the first five years while I was still not a GC holder, I wasn't sure if I'd be in the States or in Europe, because I had couple of good job offers in Germany and France. If someone is a legal alien, all the taxes and deductions listed above benefit the US citizens. Never I had questioned why they are taking Medicaid/ Medicare/ SS from me or whether I will get them back if I leave the country. Because, whether in my visa-days or GC-days, I always thought I am enjoying many facets of this country, I should contribute to the society as well. Never I had a thought this is 'Taxation without representation', because it's simple - till you're a Citizen, you can't vote and you can't get 100% benefits as the citizens are getting. It's true in all nations.
There are high caliber engineers and scientists, who want to contribute for the betterment of this country, still in queue for the last 8 years, following the process, dreaming that dream, and working hard but with a tension of GC application being rejected by the DHS! And most of them have been contributing to the society by creating jobs and paying taxes.
I have my own tech company now, and I happily employ legal US citizens - a fashion I have been following the rules from day 1.
People who are questioning about "the benefits" by paying back fines, penalties, knowledge of English & US civics by undocumented aliens, a question for you: what benefits did/do the legal aliens expect? We don't - living here, fulfilling the dreams are big benefits by itself.