Monday, April 3, 2000; Page A18

President Clinton will visit Colorado on the eve of the first anniversary of the Columbine High School shootings to promote a state ballot initiative that would require background checks for firearm purchases at gun shows, a senior White House official said yesterday.

White House Chief of Staff John D. Podesta said the trip also would attempt to increase pressure on Congress, where the Republican leadership has blocked consideration of gun-show background checks at the federal level. Clinton will be in Colorado on April 12, White House officials said.

"We're going to continue to press the case with the public that they ought to do it, and in the meantime, I think the president is going to try to use his efforts and his bully pulpit to go out and deal with state initiatives that are dealing with this," Podesta said on CBS's "Face the Nation."

Gun-show background checks became a major political issue after it was revealed that two of the weapons used in the Columbine shootings last April 20 were purchased at a gun show. Twelve Columbine students and a teacher were killed by two students, who then killed themselves.

Proponents of the background checks argue that gun shows are unregulated arms bazaars where ordinary citizens sell weapons without any of the restrictions and file-keeping required of licensed firearms dealers. Opponents claim the proposed regulations are cumbersome and unworkable.

Clinton has challenged Congress to enact the gun-control measures before the Columbine anniversary. In recent weeks, the president has found himself the target of intense criticism in a television advertising campaign by the National Rifle Association.