Republicans would be happy to have any of the current six leading candidates as their nominee for president, a new HuffPost/YouGov poll finds, but their opinions of several of those politicians, mostly notably Sen. Rand Paul (R-Ky.), have cooled somewhat in the past two months.

In April, about two-thirds of Republicans and independents who lean toward the Republican Party said they'd feel positively about nominating Wisconsin Gov. Scott Walker, Marco Rubio (R-Fla.), Sen. Ted Cruz (R-Texas) or Paul. A smaller majority said they'd be happy with former neurosurgeon Ben Carson, while just 42 percent said the same of former Florida Gov. Jeb Bush.

Impressions of Paul, though, have become more muddled in the past two months. In the recent polling from June, just 43 percent of Republicans and Republican-leaners said they'd be enthusiastic or satisfied to have Paul as their nominee, down 23 points from April.

GOP candidates' ratings -- just like their numbers in horse race polls -- will likely continue to fluctuate in the months to come, as more Americans tune into the campaign and Republicans continue to acquaint themselves with an ever-expanding field of challengers.

Some of the recent change may represent a natural dropoff from a bump in support for Paul immediately following his announcement in early April. He also riled some Republican colleagues with his high-profile stance against NSA data collection . A recent survey found that Republicans favored limiting government surveillance, but still wanted to renew provisions of the Patriot Act that allowed the NSA to collect phone data.

Rubio, who also announced his candidacy in April, and Walker, who has yet to formally launch a run, also saw enthusiasm about their prospects drop modestly.

In contrast, Bush, who announced his 2016 bid last weekend , may be enjoying a bounce of his own. Republicans now say by a 9-point margin that they'd be enthusiastic or satisfied with his nomination rather than dissatisfied or angry, making him a slightly more popular choice than Paul.

The HuffPost/YouGov poll consisted of 1,000 completed interviews conducted June 15-17 among U.S. adults using a sample selected from YouGov's opt-in online panel to match the demographics and other characteristics of the adult U.S. population.

The Huffington Post has teamed up with YouGov to conduct daily opinion polls. You can learn more about this project and take part in YouGov's nationally representative opinion polling. Data from all HuffPost/YouGov polls can be found here . More details on the poll's methodology are available here .

Most surveys report a margin of error that represents some, but not all, potential survey errors. YouGov's reports include a model-based margin of error, which rests on a specific set of statistical assumptions about the selected sample, rather than the standard methodology for random probability sampling. If these assumptions are wrong, the model-based margin of error may also be inaccurate. Click here for a more detailed explanation of the model-based margin of error.