I believe Woodrow Wilson married his second wife while an incumbent President, too, though I am not going to try to strain my glacial ISP to download a Google search to verify that.
My favorite White House Wedding trivia fact, though, is that F.D.R. and Eleanor Roosevelt were married at the White House. And the President, Theodore Roosevelt, gave away the bride – since E.R. was his niece, the daughter of his deceased brother.
Well why would you besides the novelty of doing so? What connection does the White House have to Jenna Bush besides that lots of people think her parents “live” there? Would you want to get married at your dad’s office?
I don’t know, it’s a habit I picked up a long time ago in writing to differentiate what are my choice of words from someone else’s choice of words when quoting them as a way to set off the fact that I’m not using said word/term/stupidity. Call it a grammatical smiley.