The author doesn't make it clear if it is the same speech.
I believe the President still does drive on his ranch in Texas, although the SS probably discourages it anywhere else. This is most likely where the First Lady is refering to.
It was not the same speech. The drove-into-the-wall speech was when he was running for congress in Texas. Laura was at the white house when she told him she didnt like the dead or alive saying.