By Lester Holt, NBC News anchor

It's an old travelers joke: Even on the way to Heaven you'll have to change planes at O'Hare. (There's also an Atlanta Hartsfield version of the joke).  Let's hope not.  Chicago's busy airport is for a second day in a row the root of some major flight delays keeping holiday travelers from reaching their destinations on time.  Fog and low clouds are slowing operations at O'Hare , and since it is a major hub to two of the nation's two biggest airlines, problems there are having a ripple affect across the system today.  We'll be reporting on the holiday weekend travel picture on Nighty News this evening.

This is not only a big weekend for last minute shoppers.  There is also a lot of last minute campaigning under way.  The presidential candidates are doing their best to get on the radar of all those undecided voters in Iowa before they head home to be with their families for Christmas.  In terms of useable campaign days before the caucuses we are almost to the point where you can count them on one hand.  NBC's Savannah Guthrie will be covering the races for us tonight with emphasis on those undecided voters. We'll also hear from GOP candidate Rudy Giuliani who for the first time is offering details on the health problems that caused him to have his plane turned around this week. Bloggers and pundits have been speculating and weighing-in on this all week, and now the former New York mayor is providing some answers.

Kerry Sanders reports on the joy and anger surrounding the release of a young American suddenly released from a Central American prison where he was serving a 30-year sentence for murder.

Those and other stories including a look at the debate over what rights, if any,  should be afforded to college students whose immigrant families are living in this country illegally.

As always, a big thanks for checking in.  We'll look for you tonight on NBC Nightly News.