NYT:

Despite a wealth of choices in a crowded primary field, the vast majority of high-level Republican donors and fund-raisers have not yet backed any candidate financially, magnifying the importance of the coming debates as the presidential hopefuls seek to impress potential backers.

Only about a fifth of the 1,000 or so fund-raisers and their spouses who rallied around Mitt Romney, the Republican nominee in 2012, have given money to any of the 2016 candidates, according to a New York Times review of fund-raising records reported by the candidates last week.

Those who remain uncommitted — hundreds of volunteer “bundlers” who could collect contributions from their friends and business associates — represent a huge pool of untapped campaign cash, potentially hundreds of millions of dollars, that could remake the primary campaign.