What? do you think non-citizens don't pay taxes?
Non-citizens pay at least the same taxes as citizens, I recall there being some write offs that were only applicable to citizens so it's possible that non-citizens pay more in some cases.
Obviously non-citizens also pay the same sales taxes as citizens.
The only difference is you don't get a say in how your tax dollars are used. So much for "no taxation without representation".
Oh, and have to budget time for "random" delays at airports.