It doesn't surprise me at all. Both the Tories and Labour governments have been fucking over Rochdale for years. The town is a shadow of what it once was.
Galloway's main appeal to people in Rochdale was pointing out that you can't be born in Rochdale unless it's in an ambulance on the way to Oldham, you can't be educated in Rochdale if you have any special educational needs, and you can't die in Rochdale unless it's in an ambulance on the way to Oldham.
In the past couple decades they've had their hospitals, aged care and education all cut to save costs.
He was telling Rochdale folk in a town hall debate that even if they disagree with his beliefs (i.e. Catholic views on gender and sex), he's the only one with a stake in actually doing anything for them, and Rochdale apparently agrees.
Edit: I'd encourage folks who think GG is just grifting with his rhetoric on Gaza to go back and view the archives of his talk show; it's been an issue of contention for him for decades. You can go back even further, as far back as standing in the pickets with Scargill in the miner's strikes. If he's a grifter, he's awfully bad at it considering he somehow always ends up on the right side of history (which has also been the losing side, and the less profitable side) since before most of us were born.