As is usually the case for Democratic candidates in Bucks County (and elsewhere), Harvie is an insider pick, who will no doubt win the endorsement of BCDC and, if challenged, win the primary; endorsed candidates enjoy ample support and a spot on the sample ballot handed to those who show up to vote in person.
Fitzpatrick will continue to garner reluctant support from MAGA voters, and from low-information moderate voters with a vague affection for his brother Mike. Any Democratic candidate faces an uphill path to victory.
In my limited personal dealings with Harvie, I have found him to be sincerely middle-of-the-road, and genuinely concerned about his constituents. He's an impressive communicator who takes umbrage when his decision-making is questioned, to a degree no more or less than most pols. Overall, I trust Harvie to represent my interests in Washington.
The last close congressional election in Bucks County occurred in 2018, when Scott Wallace committed millions from his personal fortune to take on Brian Fitzpatrick. Wallace lost because he emphasized his personal dislike for Donald Trump over a commitment to improve the lives of his prospective constituents. In the words of one Bucks County politician, he "never grew as a candidate." Harvie should learn from that blunder, and early indications are that he has.