Tennessee Gov. Bill Haslam has made his qualms clear, but if he caves to pressure and signs legislation making the Bible his state’s official book, he would invite a potentially embarrassing thrashing in court, some legal experts say.

The state legislature gave the bill final approval this week, undeterred by Tennessee Attorney General Herbert Slatery's forceful legal analysis last year that the bill would violate the First Amendment’s Establishment Clause and the state constitution, too.

Slatery, like Haslam a Republican, found the legislation “when viewed objectively, must presumptively be understood as an endorsement of religion and of a particular religion."

"Irrespective of the legislation’s actual purpose, common sense compels the conclusion that designation of the Bible as the official state book in practice and effect conveys a message of endorsement," he wrote. "Such an endorsement violates the Establishment Clause of the federal Constitution.”

The bill nonetheless sailed through the state legislature with overwhelming support, passing the state Senate in a 19-8 landslide after winning comfortable 55-38 passage in the state House.

Haslam spokesman Dave Smith said in a statement “the governor has constitutional questions and personal reservations about this legislation" and is "currently reviewing" the bill, which has yet to be transmitted to his office, an action that starts a 10-day clock for his decision, Sundays excluded.

Veto overrides in Tennessee require a mere majority vote in each legislative chamber, meaning Haslam’s decision may not be the last word.

If it does become law, some scholars believe it clearly would be vulnerable to a lawsuit.

”Singling out the Holy Bible for special recognition raises serious Establishment Clause and state constitutional concerns,” College of William and Mary law professor Timothy Zick says. “The adoption of the Holy Bible would signal the state’s official approval of the good book – in the same way that adopting the Latin cross as the state’s official symbol would endorse religion.”

UCLA law professor Eugene Volokh says “the Tennessee attorney general got it right” in concluding the bill would violate the Constitution’s Establishment Clause.

“Whether it violates the Tennessee Constitution’s provision ‘that no preference shall ever be given, by law, to any religious establishment or mode of worship’ is a harder question,” he says, “since it turns on whether ‘preference’ can include statements in support or would require some tangible benefit.”

The legislation is not universally considered to be in legal jeopardy, however, particularly among Christian conservatives who say the designation is perfectly constitutional.

“The Establishment Clause requires government neutrality toward religion, [but] this particular selection of the Bible [as the state book] does not require anyone to read the Bible, it does not require anyone to observe or adhere to the teachings of the Bible,” says Horatio Mihet, chief litigation counsel at Liberty Counsel, a socially conservative legal group.

“They can lawfully and constitutionally select the Bible to be the official state book given the importance of the Bible to the state of Tennessee – doing so is no more an affront to the Constitution than is selecting the state beverage or the state animal,” he says. “It is simply a factual acknowledgment of the undisputed historical fact that the Bible was important to the foundation of the nation and of Tennessee and that it’s important to the citizens of Tennessee.”

Liberty Counsel famously provided representation to Kentucky county clerk Kim Davis when she refused to issue same-sex marriage licenses last year following the Supreme Court ruling that gays and lesbians have a right to marry, and the group is willing to step in to defend Tennessee’s Bible legislation, should state officials decide against doing so, Mihet says.

Mihet says a series of court rulings that have upheld the closing of schools and government offices on Good Friday may provide legal grounding for his position, though he's not aware of any other state declaring the Bible an official book. He adds that his legal analysis would not change if a non-Christian religious text were selected by a state or local government as an official book. Cities with large Muslim populations could constitutionally make their official book the Quran, he says.

“I think if the citizens of Dearborn, Michigan, would allow their elected officials to make that declaration, it would be within their prerogative,” Mihet says.

Tennessee's state chapter of the American Civil Liberties Union is an obvious candidate to spearhead litigation if the measure becomes law. But right now, the group says it’s focused on lobbying Haslam, with legal action a more distant consideration.