They all bring multiple qualities to the table which will help, especially given the trash they are running against.
I do think Shapiro is a bonus when it comes to Pennsylvania, but she's going to carry the Keystone state anyway. Pennsylvania always gets a lot of media attention because it has a lot of electoral votes, is in the Northeast and helps the media ratings. Democrats have had solid support there since the fiasco in 2016 of low turnout, and the Stein vote that cost Hillary the election. It's increased, not decreased. Harris will win it by somewhere between 4 and 6 points.
Shapiro brings a sharp minded, articulate, sensible voice along with him who would bury J.D. Vance in a debate, and who can explain, in layman's terms, things voters can understand. Walz brings his expertise and understanding of governing in the midwest, a microcosm of the rest of the country. Buttigieg is also the articulate explainer who doesn't let the narrative get away from him. Beshear is a masterful politician who has maintained popularity in a red state and his asset may be in talking enough red state voters into voting for Harris in places like Ohio and North Carolina. I like Mark Kelly a lot, the senator from my home state, but I think he does more for us in the Senate at this point, and they need to send Kari Lake packing in Arizona and he's teamed up with Ruben Gallego to do it.
The bottom line is that this is a critical decision but they're all good choices with good reasons behind them and none of them will hurt this effort at all. We need to win and we need to get the House and keep the Senate, and I think that's going to happen.