Should a Christian Make this Pledge?

I do solemnly swear (or affirm) that I will faithfully execute the Office of President of the United States, and will to the best of my ability, preserve, protect and defend the Constitution of the United States.

That means that whoever is elected president must protect the legality of abortion, even while they act to challenge it, and that pledge is made publicly and with their hand on the Bible. Even a believer taking an oath is Biblically questionable, but when the Supreme Court legalizes abortion, or gay marriage, or anything that goes against God’s Word, the president has pledged an oath with his hand on God’s Word to protect and defend the process that is against our God.

BTW - Nowhere in that oath is there a pledge to defend the Bible or follow Jesus Christ. Quite curious for a “Christian nation”.