Controversial business tycoon Donald Trump is still leading the pack of Republican presidential contenders, but his closest rival is eyeing to grab the lead from him anytime soon.

The camp of neurosurgeon and Republican presidential hopeful Ben Carson has pledged to eclipse Trump as the race to the White House heats up in the coming months.

"Clearly we're behind [Trump] in the polls, but we are of a similar speed and a similar type of vehicle behind him that carries a lot of the same message," Carson's communications director Doug Watt said.

"We have a similar songbook. We're just singing in a different key," he added.

Both Carson and Trump have been critical of US President Barack Obama's administration, but the former has been soft-spoken while the latter has made some controversial public remarks.

The two leading Republican presidential bets are also banking on the support of two key groups: evangelical Christians and Tea Party backers.

How exactly does Carson's camp intend to catch up with Trump? Watt said the neurosurgeon will use the "slipstream" strategy.

In cycling or car racing, this strategy means letting the frontrunner enjoy his lead throughout the race, then overtaking him before the race ends.

Also, Watt pledged that Carson will maintain a "positive" campaign—contrary to Trump's style of attracting controversy.

"We intend to be positive throughout the primary campaign," Watts said.

He added that Carson has pledged "not to return fire" in case he becomes the target of Trump's attacks.

Andy Yates, a North Carolina-based political consultant and executive director of One Vote, for his part, said the public's interest on Carson, including that of potential investors, "just continue to rise." In fact, Carson reportedly raised millions in campaign funds during the past month.

"I think you'll see a lot of Trump supporters move to Carson as they start to get tired of the outlandish," Yates said.