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."