The pledge is part of the Iowa GOP's effort to protect the state's status as host of the first presidential caucuses. State party officials had set Wednesday as the deadline for presidential hopefuls to sign a pledge to boycott Louisiana unless it rescheduled its caucuses to follow Iowa's.
The Louisiana caucuses are set for Feb. 6, Iowa's for Feb. 12.
Among the GOP candidates, Sen. Phil Gramm of Texas previously had refused to sign the Iowa pledge. Senate Majority Leader Bob Dole, former Tennessee Gov. Lamar Alexander, Indiana Sen. Dick Lugar and publisher Malcolm S. (Steve) Forbes Jr. have sided with Iowa and signed the pledge.
In a letter to Iowa Republican Chairman Brian Kennedy, the Buchanan campaign said it supported the tradition of Iowa going first but that it would not boycott Louisiana because "Pat has made a commitment to a good many people" there.
Gramm is believed to have the deepest support in Louisiana. Even as Buchanan refused to sign Iowa's pledge, he blamed Gramm for Louisiana's effort to leapfrog Iowa.
"In this sustained, cynical campaign to seize early momentum for Mr. Gramm in the presidential race, decades-old traditions are being trampled under foot," Buchanan said in a statement.
Gramm has denied that he helped orchestrate the date of the Louisiana caucuses.
Iowa GOP leaders have not ruled out holding their event earlier. But rescheduling the caucuses would be a daunting logistic task, and Iowa Republicans had hoped that Louisiana would back down and reschedule its event if all the major GOP candidates signed Iowa's boycott pledge.
Kennedy, the Iowa GOP chairman, said he was disappointed by Buchanan's decision. "I think it can have an adverse impact on his campaign" in Iowa, Kennedy said.