Arthur Finkelstein, a reclusive political Svengali who revolutionized campaign polling and financing and helped elect a bevy of conservative candidates, including President Ronald Reagan and Prime Minister Benjamin Netanyahu of Israel, died on Friday night in Ipswich, Mass., where he lived. He was 72.

His family confirmed the death in a statement. The cause was lung cancer.

Mr. Finkelstein was among the first political strategists in the late 1970s to grasp the potential of a United States Supreme Court ruling that allowed putatively independent political committees to spend money on behalf of individual candidates and causes.

The decision led to a proliferation of fund-raising vehicles that were supposed to be beyond the control of candidates or party officials but that in fact often worked in concert with their campaigns. One such group, the muscular National Conservative Political Action Committee, was established with Mr. Finkelstein’s help.

He also pioneered sophisticated demographic analyses of primary voters and methodical exit polling, and of using a marketing strategy, called microtargeting, to identify specific groups of potential supporters of a candidate regardless of their party affiliation.