Senate Majority Leader Bob Dole has decided to replace his top strategist and fire his lead pollster in an effort to revive his struggling presidential campaign, sources said Sunday.

The shakeup comes after back-to-back defeats that have the once overwhelming GOP front-runner battling for survival.

The moves follow weeks of often bitter turmoil within the Dole campaign over strategy and advertising.

Dole made the decisions late Saturday after being told he would lose Delaware’s presidential primary to Steve Forbes - despite being assured earlier that he was leading in the state and likely to win.

The dramatic internal campaign reorganization is but one reflection of the urgent mood within the Dole camp. After a razor-thin victory in Iowa, Dole has now run second in New Hampshire and Delaware and is in a tight race here in Arizona, where polls show a narrow Dole lead but GOP activists give Pat Buchanan solid odds of winning Tuesday’s primary.

In the shakeup, pollster William McInturff and his firm, Public Opinion Strategies, will no longer be given any Dole campaign business, according to campaign sources who spoke to The Associated Press on condition of anonymity.

And William Lacy, a longtime Dole adviser, was told he was being removed as chief strategist with control over polling, advertising and other campaign media, the sources said. Lacy was told he could stay in and keep his title as deputy campaign chairman, but that he would lose most of his authority, the sources said. It was unclear whether he would stay with the campaign.

The top strategy role was turned over to Don Sipple, a veteran GOP consultant who joined the Dole campaign after California Gov. Pete Wilson quit the race last year. Sipple has been frustrated for months as his advice was ignored or overruled by Lacy.