Illegals?
Nope
They have legal rights but not the benefit of enhanced constitutional rights
That is reserved for citizens.
Wrong. Where does the Government get the authority to do anything or to interact with any human being in the world? Through the Constitution. So where in the Constitution does it say that the government can search illegal aliens without a warrant or probable cause? Where does it say that they can convict an illegal alien just on the decision of a judge without a jury? Where does it say that they can publicly castrate illegal aliens, without a trial and without a lawyer, for jaywalking?
The government can't wipe their ass unless the Constitution says it is so. Samuel Adams said, and I attributed this to John Adams yesterday, making it clear that I was going from memory but i have verified that it was Samuel Adams who said, "
The Constitution shall never be construed... to prevent the people of the United States who are peaceable citizens from keeping their own arms.”
We tend to take our attention to either "peaceable citizens" or "keeping their own arms", depending on our objectives but the greatest part of this statement is, "The Constitution shall never be construed..." This highlights that the Founders believed that the Government could not do a thing, it doesn't matter what the thing is, because the Constitution cannot be construed to give them the authority.
If you cannot construe that the Constitution empowers the Government to even have an official conversation with an illegal alien outside of the restraints or authorities identified in the Constitution, then they cannot have it. And the Constitution cannot be construed to allow the Government to refuse an attorney to an illegal alien or to punish them without trial or to inflict cruel and unusual punishments upon them.
Your question does not make clear what the goal of the question was or if you have a particular constitutional protection that you're concerned about illegal aliens enjoying but where I usually see this question is about the 2nd Amendment and the right to keep and bear arms that it protects.
The 2nd Amendment doesn't mention citizens; it mentions the people. The Founders were able to distinguish between the meanings of "the people" and "citizens" as the two were used appropriately throughout the Constitution.
So, like I said, you didn't make it clear what you're really trying to show but this question is always about something more than just a general thought about the protections of the Constitution so do enlighten us about what you're really trying to prove.