The poll, conducted by Maverick Opinion and reported by the Post-Gazette, asked 447 Republicans in the district.
Campaign spokesman Ray Zaborney said the results show voters “want a conservative fighter who will stand up for Donald Trump’s agenda and that’s Bill Shuster.”
The release of the poll comes about two weeks after Halverson released a poll showing he was only trailing 38-36 with 26% undecided.
Campaigns will commission these types of polls and only publish the results that show them in the best position.
Halverson, who ran against Shuster in the 2014 and 2016 primaries and as a Democrat against Shuster in the 2016 general election, will reportedly make an announcement next month about his plans for 2018.