They play in the American Athletic Conf (a weak conf) and they've only played two decent teams this year and lost to both.
Their #1 WR, #1 TE and best Def End are in the portal so they may not play. They also have quite a few backup def backs in the portal.
Even with these items, I think its crazy Tulane is a double digit dog. They are much closer in ratings than the line indicates.