“Why walk it back?”
Because, here in the U.S.A. we do not put foreign dignitaries, even allies that we really like, on our currency.
True enough, so it'll never happen anyway.
Picking The Iron Lady was a pretty good choice, and gor the attention of conservatives - it got our attention, because we're talking about it right now.
But Jeb walking it back just makes conservatives say, "Meh, never mind. We were right all along, he's just a spineless mush, even on the stuff that he did right."
I'm not Trump's biggest fan, but I liked his give and take with Bush. It was easy to see who the Alpha Male was:
Bush: "Apologize to my wife!!"
Trump: "No."
Bush: ".................................... Ok. Moving on to immigration..."
Showed that Jeb was A) dumb for engaging Trump and 2) Spineless.