NASHVILLE (AP) - The effort to strip Vanderbilt University of its police force over a nondiscrimination policy for student groups has brought up a traffic stop involving the chairwoman of the Senate committee handling the bill, but the lawmaker says she doesn't know why the incident has become part of the debate.

David Fowler, president of the Family Action Council of Tennessee, said the senator, whom he didn't identify at a Tuesday news conference, had been stopped on a major Nashville thoroughfare bordering campus.

Fowler cited the stop an example of police activity he wants to curtail through legislation if the private university does not stop enforcing its nondiscrimination policy among student groups.

The Vanderbilt policy prohibits discrimination based on race, sex, religion, color, national or ethnic origin, age, disability, military service, genetic information or sexual orientation. To be sanctioned by the university, student groups must open membership to all students and allow all members in good standing to seek leadership posts.

Christian groups have protested the policy, saying it forces them to allow nonbelievers and gay students to join. Vanderbilt officials say about 15 student groups have refused to comply with the policy and more than 480 groups have accepted it.

University spokesman Jim Patterson confirmed to The Associated Press on Wednesday that Republican Senate Education Chairwoman Dolores Gresham of Somerville was given a verbal warning after being stopped on the evening of Feb. 4 for driving without her headlights on.

Patterson said the officer described the stop as amicable and that Gresham was "very thankful" to the officer for alerting her that her lights were off, saying that they are usually turned on automatically.

Gresham did not appear to recall the incident when asked about it by the AP on Wednesday. She said she would speak to Fowler about why he brought it up in the press conference.

Lawmakers last year passed a bill to ban any other school from enforcing an "all comers" policy, but Republican Gov. Bill Haslam vetoed the measure because it also targeted a private institution.

This year's bill sponsored by Sen. Mae Beavers, R-Mt. Juliet, was scheduled for a hearing in Gresham's committee on Wednesday, but Fowler said supporters had agreed to put off a vote for a week so Haslam could seek an attorney general's opinion about wither it is constitutional.