Jeb Bush makes his way to an Uber car after speaking at Thumbtack, an online startup, on July 16. (AP/Eric Risberg)

Out on the campaign trail, Jeb Bush eagerly engages voters looking for a hug, a handshake or a photo. Usually he works a room with just one aide by his side and travels with a team that can fit into one SUV.

At multiple stops in recent days, there's been a new member of Bush's entourage: A bodyguard.

Being the son and brother of former presidents doesn't afford Bush U.S. Secret Service protection -- but given his family ties, the desire for some security perhaps isn't surprising.

According to campaign finance reports released this week, Bush's campaign has paid $9,892.85 to U.S. Safety & Security LLC for security services. Campaign aides confirmed that the money was spent on security, but declined to say if there have been specific threats made against him.

In San Francisco on Thursday, a private security agent dressed in a suit and tie kept his distance, but watched as Bush arrived and spoke at a morning campaign event. Recently in New Hampshire while marching in two Independence Day parades, a different man wearing dark sunglasses and a black, short-sleeved, button-downed shirt kept just a few paces away from Bush and at one point stepped in with other aides to keep a hectoring climate change activist from blocking the candidate's path.

Bush's security firm of choice is based in Severna Park, Md. and provides protection for corporate and political clients, including security at large events, bodyguards for top executives, consulting for large hotels or stadiums and disaster management. Guards employed by the firm provided security for 2012 Republican presidential candidate Mitt Romney before he picked up U.S. Secret Service protection as the GOP nominee.

Company president Joseph Funk did not respond to a request for comment.

So far, Bush's security costs are significantly less than several other candidates who travel with security details -- often at taxpayer expense.

Flanked by Secret Service agents, Hillary Rodham Clinton marched in the Gorham, N.H. Fourth of July parade this year. (Darren McCollester/Getty Images)

Former first lady and secretary of state Hillary Rodham Clinton remains under the protection of Secret Service agents. She travels in armored vehicles and is always flanked by agents. People attending Clinton campaign events must undergo checks similar to airport security screening. When Clinton marched in an Independence Day parade in New Hampshire, campaign aides kept reporters behind a moving rope line, saying later that the Secret Service had requested the move.

Four Republican governors running for president -- Chris Christie (N.J.), Bobby Jindal (La.), John Kasich (Ohio) and Scott Walker (Wis.) -- also travel with small teams of state police officers, whose services cost taxpayers millions of dollars.

Christie has faced the most scrutiny for his security costs. Records released last week show that travel expenses for his security detail cost more than $184,000 in state funds over the first three months of the year. Christie's out-of-state security bill in 2014 cost $492,420, according to state records.

Christie has acknowledged the taxpayer costs, but so far has no plans to reimburse the state. Aides have noted that there is no state law allowing him to do so.

Walker usually travels with a team of two or three burly state troopers. In several instances, the men quickly have formed a muscular wall between the governor and reporters at campaign stops or if an attendee suddenly asked a tough question. Earlier this year, Walker's political entity, Our American Revival, started paying for Walker's political travel, including his security team. But in 2014, Wisconsin taxpayers spent roughly $2.4 million on security for Walker, his family and the lieutenant governor when they traveled out of the state.

Wisconsin Gov. Scott Walker speaks at Red Rock Harley-Davidson on July 14, in Las Vegas. (Ethan Miller/Getty Images)

Aides to Kasich have refused to say who is paying for the highway patrol officers that travel with him on political trips outside of Ohio.

"For the safety of the governor, his family and those with him, we simply never discuss security procedures or resources," Kasich spokesman Rob Nichols told the Northeast Ohio Media Group last week.

Jindal's security costs appear to be among the largest. In March, the head of the Louisiana State Police said his agency had spent $2.2 million on travel expenses for the security detail during the most recent fiscal year. In January, it cost $73,000 for seven state troopers to protect Jindal and his family during a 10-day trade mission to Europe.

Rick Perry, the former Texas governor, traveled with a state police detail until he left office earlier this year. His campaign expense report showed that four individuals were paid a total of $975. A campaign spokeswoman said that the four guards only provided protection during Perry's campaign launch at an airplane hanger outside Dallas in early June.

Besides Bush, at least one other Republican presidential candidate is also employing private guards: Donald Trump.

The real estate magnate travels with several guards who wear dark suits and radios and earpieces to communicate. On their lapels, the guards wear small white buttons with "TRUMP" written in black letters.

Trump's campaign spending report shows two line items listed as "Security" for $1,000 each. A campaign spokeswoman didn't return requests for comment about the fees.

Anu Narayanswamy, Jenna Johnson and Robert Costa contributed to this report.