More than a half-dozen likely Republican presidential hopefuls have been barnstorming the early primary states for months now, but a majority of Americans can't name a single one of them.

Pew Research survey released Wednesday showed the results of asking this open-ended question of a nationwide sample of adults: "Regardless of whom you might prefer, which Republican candidate have you heard the most about in the news recently?"

Twenty-six percent of respondents named real estate mogul Donald Trump, but 53 percent couldn't name a single candidate in response to the question.

Sixty-one percent of Democrats were unable to name a candidate, as were 50 percent of self-identified independents.

Trump was the only rumored hopeful to garner double-digit recognition. His 26 percent was followed by former Massachusetts Gov. Mitt Romney, whose name was volunteered by just 9 percent. 

Another 4 percent said former Alaska Gov. Sarah Palin, and 2 percent named former Arkansas Gov. Mike Huckabee. The names of former House Speaker Newt Gingrich and former Minnesota Gov. Tim Pawlenty were offered by 1 percent of respondents.

Trump's potential 2012 bid has garnered extensive media coverage in recent weeks as he continues to raise questions about President Obama's birth certificate. Trump's hammering of the "birther" theme corresponds with an increase in his support in recent polls. 

The latest numbers from Democratic-leaning Public Policy Polling found Trump leading the GOP pack, opening up a lead of nine points over Romney.