Presidential pardon for illegal aliens?

Stephen Hayward of the Powerline blog suggests:

How about this: after the election next fall, especially if the GOP takes the Senate and with an eye to the 2016 election prospects for Democrats, Obama might well decide to use his pardon power to grant a blanket pardon to all illegal aliens presently in the United States.  This would not, strictly speaking, be a legal abuse; the president’s pardon power is unconditional in the Constitution.  But you can imagine the firestorm it would generate.

There's more at the link.

That's a pretty ghastly prospect . . . but the present Administration may be sufficiently full of itself that it thinks it's worthwhile.  Hayward suggests that a Republican response might be to impeach President Obama.  Rush Limbaugh thinks that might be just what Obama and the Democratic Party want.

Because the Democrat theory is that if they can goad the Republicans into doing that, then they will lose forever the race for the White House, and especially in 2016. The thinking is if the Republicans move to impeach the first African-American president, that this country will react in outrage. They already are predisposed to thinking the Republicans are extremists, and that will prove it, trying to impeach the first black president.

That will unite the Democrat base, and there is no way the Republicans can win. It's a protection. It's just a prediction. Hayward's not saying it's in the cards. But he does say he thinks that every reporter talking to any Democrat from now until November needs to ask that question: "If the president issues a blanket pardon as a means of securing amnesty for all of these illegals, would you support it?" He thinks every Democrat needs to be put on record answering that question.

Have you forgotten Jimmy Carter did a blanket pardon of all Vietnam-era draft dodgers? Do you recall that? Some of you are not old enough to remember that, but he did. Look, this is just a prediction by Steven Hayward at Power Line. I read it last night. Again, the thinking is that the Democrats would love for the Republicans to try to impeach Obama. They think that that alone would end the Republican Party.

Again, more at the link.

I have two very important questions about this.  I understand a Presidential pardon covers all offenses committed under United States law prior to the date of the pardon.  However:

1. I don't think a pardon can be issued to cover future offenses.
2. I don't think that a pardon equates to the granting of a new legal right - only to forgiveness for offenses previously committed.

Therefore, if an illegal alien is granted a pardon by President Obama, would not his continued presence in the USA after the date of the pardon constitute a new offense, for which he could be tried, convicted and punished?  And furthermore, would a pardon for being here illegally also confer the right to remain here legally?  I can't see how it could possibly do that, because a pardon can only restore previously existing civil rights, not grant new ones.  Surely the newly-pardoned illegal alien would have to go through the regulatory process and be granted a visa, or a Green Card, or citizenship, in order to stay here?  A Presidential pardon confers none of those things.

I'd be interested to hear from readers with a better understanding of the Constitution and laws of the United States about my interpretation of this matter.  It seems to me that if President Obama were to take such a step, he'd be opening a huge and very smelly can of legal worms . . .

Peter