Well I researched the topic and I never found an age limit to becoming a naturalized US citizen. The loop is this, to legally enter the country you must first have a Visa then you may apply for a green card which is also a permanent resident card, at that point they pay taxes and can qualify for assistance however you must prove to be gainfully employed and hold the visa for 5yrs before being eligible to apply for naturalized citizenship, you must also be able to speak english (a big problem for many immigrants I would think) and depending on age you would have to enlist for the armed services draft or something like that. Lengthy process, but the legal process. Until you are a naturalized citizen you cannot vote in an election or hold public office with exception of president or vice president. They offer special types of green cards for close relatives including parents, grandparents and such, didn't explain all the rules on those types separately so I'm still not sure. There definitely needs to be some changes on our policies to make the system run more efficiently however many of your illegals coming to America can't speak english, would be denied visas due to their criminal back grounds and someones bringing the drugs from Mexico. Many are entering the US because they cannot comply with the rules we have laid out so they just enter illegally, take low paying jobs and probably aren't living lives much better than they may have had in Mexico unless they are making alot of money dealing drugs.