Indiana Gov. Mike Pence might not help presumptive Republican nominee Donald Trump as much as conservatives hope, according to one expert.
Jared Bernstein, senior fellow at the Center on Budget and Policy Priorities, told "Squawk on the Street" on Monday that he isn't sure that Pence is the best running mate choice for Trump.
"One of the problems you have there is that he is very hard right on social issues, so those people are either already with Trump or they're a relatively small part of the base. He's completely different from Trump on so many key issues including trade, immigration, the Muslim ban, the wall," Bernstein said, adding that Pence could be "messing up his brand."
Sara Fagen, former White House director of political affairs for George W. Bush, disagreed and said that she thinks Pence "brings a lot to the ticket." In particular, she emphasized that social conservatives have not necessarily been behind Trump, contrary to Bernstein's analysis.
"The selection of Mike Pence is very helpful in that regard. It will help unify the base and give people who are concerned about Donald Trump, they will look at him differently and probably support him, whereas beforehand they were still up in the air," Fagen, who is also a CNBC contributor, said on "Squawk on the Street."
David McIntosh, a former congressman from Indiana, told "Squawk Alley" on Monday that he agreed with Fagen. He explained that Trump appeared to be a "liberal most of his life" and that picking Pence as his running mate, who McIntosh described as a "strong conservative," did in fact help the New York businessman unify the party.
Fagen acknowledged that Trump could have chosen a better running mate, especially if he had selected "somebody that could go directly against Donald Trump's weakness with women, with minorities," which Fagen argued "probably would have been a better longer-term play."
And that's exactly the problem for Republicans, according to Bernstein, who is also a CNBC contributor.
"If they don't come out of this convention with a lot more support from what I call the median voter, someone who is not to the far right — Mike Pence is to the far right — I don't think they're going to win in November," he said.
Fagen added that ultimately the top-line figures in the polls aren't what matters for Trump coming out of the convention. Fagen, a partner at DDC Advocacy, said that Trump's ability to do well with white and Hispanic voters are key to his success. She cited recent figures from an NBC poll that show Trump is getting about 50 percent of the white vote and 17 percent of the Hispanic vote.
"If those numbers held — they're both far below where Mitt Romney's was — he would get crushed. He would not lose by 5 points. He would lose by 12 points and so he's got a lot of work to do as a nominee," she said.
Fagen pointed to the lineup at the convention as a manifestation of the disunity that exists in the Republican Party. She said that the GOP under Trump is a different party and that "old-line Republicans ... are not quite sure where they fit in."
Bernstein said the slate of speakers at the convention doesn't bode well for Trump. He explained that the gathering was an opportunity for Trump to reset, but that it's unlikely "he's going to be able to do that, in part because of the establishment Republicans."
"I can't remember a convention where a president of the party for that convention didn't speak. I doubt Sara can either, at least in modern history. I think that's a big omission," said Bernstein, who is also a former economic advisor to Vice President Joe Biden.