Trump lost up to 10 points in debate: Ex-WH aide

Donald Trump has courted controversy with his outspoken views on immigration and fellow Republicans, but the billionaire businessman may have been too reserved in his first GOP presidential primary debate, a former White House aide to George H.W.

Bush said Friday.

"Donald Trump may have lost as many as 10 points some of my friends think," Joe Watkins told CNBC's "Squawk Box." "Donald Trump is best when he is unfiltered, and he wasn't as unfiltered last night as I thought he might be."

Much of the attention in the first GOP presidential debate of the 2016 campaign was on Trump, who has rocketed to the top of the polls. Before Thursday night's debate, Trump commanded a 21 to 26 percent lead in a number of polls, according to Real Clear Politics.

Trump has both come under fire and surged in polls after saying many Mexican immigrants in the United States are criminals and rapists and insisting that Republican Sen. John McCain, who was a prisoner of war in Vietnam, was not a hero.

Read More GOP debate: Winners, losers, and then there's Trump

But that brashness was not on display Thursday night, Watkins said. He noted that Trump articulated his opposition to the Iran nuclear deal instead of offering an incendiary response to a question regarding the reported meeting between an Iranian general and Moscow in violation of U.N. sanctions.

Still, the other candidates showed they are a little afraid of Trump and were "fawning" over him, said Sara Fagen, chief political strategist at DDC Advocacy Partners. She noted that Sen. Ted Cruz "awkwardly" hugged him during a commercial break and Ohio Gov. John Kasich acknowledged the spirit Trump has captured within the Republican party.

However, she said she doesn't expect Trump's lead to last.

"Ultimately I think he's going to do two or three more of these debates and he will likely not have much substance like he did not last night, and ultimately that will catch up with him," she told "Squawk Box." "But for now he puts on an incredible show."