On Tuesday, the New York Post reported Trump was vetting his top military consultant Lt. Gen. Michael Flynn for vice president. But Del Percio said she wouldn't rule out a "head fake" from the real estate developer and reality TV star.
"He likes talking about a lot of different possibilities, and he likes to surprise people," she told CNBC's "Squawk Box" on Tuesday.
The founder of Susan Del Percio Strategies said the head fake masks a pivot to Brown, the first former or sitting senator to endorse Trump. In addition to proving his loyalty long before other Republicans, Brown has the legislative experience Trump needs and his family fits the image the presumptive Republican nominee is trying to cast, she said.
Brown rose to prominence in the Republican Party after securing Sen. Ted Kennedy's seat in an upset win after Kennedy's death in 2009. He lost the seat to Sen. Elizabeth Warren in 2012.
Brown failed in his bid to represent New Hampshire in the U.S. Senate in 2014. That campaign was bookended by stints as a Fox News contributor.
His failure to secure elected office could sink his shot as Trump's vice presidential pick, according to conservative radio host and Boston Herald columnist Howie Carr. On Tuesday, Carr quoted Trump as saying Brown is "a great guy. … But I need somebody who's in office right now."
Democratic strategist Chris Kofinis said Tuesday that Brown would bring little to the ticket. Trump needs someone who can change the narrative and win establishment votes, according to the CEO of public relations firm Park Street Strategies and former chief of staff to West Virginia Sen. Joe Manchin.
He noted, however, that a dramatic vice presidential nominee could backfire, as it did when Arizona Sen. John McCain chose then Alaska Gov. Sarah Palin.
Clinton faces the same challenge in regaining the trust of the American electorate after a scandal over her use of a private email server during her tenure of secretary of state, Kofinis said. But Clinton must change the narrative on her own, he added.
While left-leaning candidates like Warren or a rising star like New Jersey Sen. Cory Booker have been floated as potential Clinton picks, Kofinis sees her choosing someone safe, such as Virginia Sen. Tim Kaine.
Del Percio also ruled out Warren, a divisive figure known for her attacks on Wall Street and for laying the foundations of the Consumer Financial Protection Bureau.
The Clinton campaign already has a personality that can detract from its candidate in former Pres. Bill Clinton, she said. It does not want to further take the spotlight off HIllary Clinton, she added.