HARRISBURG, Pa. -- Spurred by the Sept. 11, 2001, terrorist attacks and a court ruling that declared the "under God" portion of the Pledge of Allegiance unconstitutional, states increasingly are requiring that the pledge be said in schools.

Twenty-eight states require the pledge to be recited during the school day, according to the Education Commission of the States, a nonprofit national association of state education officials. Another seven encourage schools to conduct the pledge.

And others are getting on board rather than leave it up to local school districts to decide.

The Pennsylvania Senate this week unanimously passed a measure that would require students in private and public schools to recite the pledge or sing the national anthem. The bill, which already passed the House once, goes back to the House because it was amended by the Senate.

As of September, 16 states had legislation pending or passed during the 2001-2002 session that required or encouraged the recitation of the pledge in schools, according to the National Conference of State Legislatures.

"Since Sept. 11 especially, it's been an issue that legislators really rallied behind and it seems that it's something that most of them can agree on," said Greta Durr, an education-policy analyst with the NCSL.

Perhaps it is a little too easy for lawmakers to agree on the idea, said the legislative director for the Pennsylvania chapter of the American Civil Liberties Union.

"Unfortunately, too many people allow them to wave the flag and forget that they haven't done anything to improve the public schools with all this flag-waving," said Larry Frankel of the ACLU.

Frankel said the Pennsylvania bill has two problems. One is that students may be intimidated by the requirement that parents be notified if students exercise their First Amendment rights not to participate in the pledge.