(Admittedly, the scene of First Daughter Dawn Wells convincing the unconverted President Laurence Olivier to cancel Xmas at the White House, was a hoot.)
Dawn Wells still
refuses to talk about it to this day (which, ironically, is the stance her co-star on
Gilligan's Island, Tina Louise, took towards
Gilligan's Island after the show went off the air). Don't even try to bring it up to her (when someone at a
Gilligan's Island TV special brought up her role in this movie, she said it was a piece of shit--
on the air live). As for Laurence Olivier, he said in an interview right before his death that this was the worst of his late-career movies (which, if you consider
The Betsy, The Jazz Singer, and
Inchon, is
really saying something, IMO) and apologized for starring in it.
BTW, they wanted
Suzanne Somers to play the First Daughter originally, but she read the script and, thankfully, followed the advice of her then-fiancée (now husband) Alan Hamel, and turned it down. Now, if she'd only ignored his advice about leaving
Three's Company 
...
You know who they wanted to play the president originally?
Orson Welles. Welles, thankfully, turned it down (and this was a man who appeared in the movie
Butterfly with Pia Zadora, among other questionable late-career moves--except for his role in
Transformers, which he quite enjoyed)...
The only saving grace of The Power of Ten was the choice of actor to play the Antichrist--Michael York. York later admitted that he deliberately hammed it up in the role because he realized the movie was going to be awful (he also did interviews promoting the movie--where he promoted the
movies competing against it and urged viewers to watch them instead). He's widely cited as the most enjoyable part of the movie, even by the movie's detractors (it helps that he also took it for the money and because he wanted to play the Antichrist)...
(OOC: For an idea of how York would play the Antichrist, watch Michael York as the Antichrist in the Omega Code movies, where he chews up the scenery...)