Jeb Bush has the support of just one percent of likely Republican caucusgoers in Iowa, according to a new poll from CBS News. The poll, released Sunday, found Bush with the same level of support as Carly Fiorina, Rick Santorum, and John Kasich. That puts Bush behind Chris Christie (2 percent), Rand Paul (3 percent), Ben Carson (5 percent), Marco Rubio (13 percent), Ted Cruz (34 percent), and Donald Trump (39 percent).

The poor numbers for Bush come nearly a month after Right to Rise, the super PAC supporting the former Florida governor, made a $25 million ad buy in both Iowa and New Hampshire that aimed to tell "Bush's story." Right to Rise also reportedly spent $1.4 million over two weeks in January to run negative ads on Iowa TV about GOP rival Marco Rubio.

Other recent polls of Iowa don't have Bush performing quite as badly as CBS, and the Real Clear Politics average of polls there shows him with 4.2 percent support, coming in fifth behind Carson, Rubio, Cruz, and Trump. But with the Iowa caucuses just a week away, Right to Rise senior strategist Mike Murphy's hope that the race would come down to a one-on-one contest between Bush and Trump looks farther out of reach than ever before.