Require that all federally elected office holders swear an oath on the US Constitution

Elected federal officials should be required to swear a solemn, secular oath on the US Constitution, as it is a tangible reminder of the duties required of them. The US Constitution was created by the Founders to preserve the rights of the people, guard against the dissolution the Union and prevent undue power from being accumulated in the hands of a few at the expense of the people.
Swearing on a bible, which does not fully encompass the beliefs of any one people of the United States, should be secondary to swearing on the document of the Union itself.