Battle for GOP Donors Reignited After CNBC Debate

Pressure Mounts for Jeb Bush to Boost Sliding Poll Numbers 1:12

Donors and supporters of Jeb Bush's presidential campaign are reeling after Florida rival Marco Rubio swiftly rebuked a Bush attack on the amount of votes the senator has missed while running for president during Wednesday's CNBC debate.

NBC News learned Thursday that Bush promised his donors on a conference call that he would improve as a candidate, while Rubio is working to recruit Bush fundraisers who me be looking to jump ship. Even loyal Bush backers told NBC News that they are frustrated and feel like their candidate did not live up to the expectations set for the important moment.

Meanwhile, Rubio and Texas Sen. Ted Cruz both saw a fundraising spike after the debate where both were largely thought to have performed well.

Ted Cruz, Marco Rubio Riding High With Fundraising After Third Debate 1:57