The law does not require elected officials to be sworn-in using a Christian bible

[gratuitous]

6. Keith Ellison took his oath of office on a Koran

Which seems appropriate for a Muslim.

However, there are also Christian sects that don't believe in swearing on or by anything (citing Jesus, who said "let your yes be yes and your no be no" and that any further embellishment was evil). For those people, the law allows them to make their statement by affirmation, and swearing an oath on the Bible would be considered by them to be quite sinful, if not outright blasphemous.

In the clip, Ted Crockett looked like he was trying to catch a fly buzzing around the studio.