HOUSTON- Several Republicans have asked Donald Trump to step down after a video surfaced of him making lewd comments about women that he has since apologized for. Our team of researchers looked into whether or not stepping down is even an option.

Republican party rules state that party leaders can pick a replacement if a nominee withdraws. “Rule 9” was created in case of a candidate's "death, declination, or otherwise.”

If this were to happen, the 168 party leaders would then need to name a replacement. Experts say in this case it would likely be Mike Pence.

But those rules apply to the Republican party, whether voters could choose a new candidate would depend on 50 different sets of state laws.

For most states, registration deadlines have passed. Legally, they don't have to change their ballots.

Early voting is already underway in 14 states and hundreds of thousands of votes have already been cast with Trump’s name on it.

Thirty-seven states and Washington D.C. have early voting, including Texas.

As a final resort, Republican leaders could urge voters to write-in Mike Pence or Mitt Romney to try and win the electoral college vote, but that could run into state-by-state issues.

Trump told the wall street journal over the weekend that there is "zero chance" he will withdraw.