There hasn't been an issue as politically potent as illegal immigration in at least a generation. It could even realign the political landscape on a scale similar to the New Deal.
It's time for the "leaders" to get out in front of the crowd--or cease to be leaders.
Hillary's health care plan, and its defeat, in 1994 resulted in the Republican takeover of Congress. That was at least as potent as illegal immigration, if not more so.
Sometimes you just have to bite the bullet and do what needs to be done.
As for Guiliani, no from me.
McCain, I'll sit home and watch fresh paint dry.
No, it can't. The basic problem with your assessment is that this issue is only "politically potent" on one side of the aisle -- or, more accurately, on the "incumbent" side of the aisle.
One of the great advantages of being an opposition party is that you never have to come up with workable ideas yourself. You simply have to sit back and complain that the ruling party is doing something wrong, and "We'll just do it better" is seen as a perfectly legitimate point on issues where the opposition party has no intention of coming down on the other side of an issue (think back to Kerry's lame campaign points on the Iraq war as a perfect case in point).
This issue cannot realign the political landscape for one simple reason -- because both major parties are basically on the same side.