Funny enough she either does not know history or she was not thinking about EVs when she picked him; since if I remember correctly MN has voted for dems in presidental elections for decades. Yet one of the big things with the PA governor was him being from a swing state where people may actually use that as a tie breaker of sorts.
Minnesota last voted Democrat in 1972 and thus is the state the least recently voted Republican (even in Ronald Reagan's crushing victory in 1984, Minnesota was the
only state that didn't vote for him). That said, even though it constantly ends up voting Democrat, there were some elections where the Republican was close to winning, like how Hillary only beat Trump by 1.5% in 2016. So it's a state that's at least theoretically in play.
However, in regards to the larger question of trying to win a swing state with a vice presidential candidate, that doesn't actually seem to be a common strategy. Here's the breakdown of 2020 through 2000:
2020:
Neither Pence (Ohio) nor Harris (California) were from swing states.
2016:
Pence was not from a swing state, though Tim Kaine (from Virginia) was. Hillary did narrowly win Virginia so perhaps that did help, though she lost the election overall.
2012:
Biden was from Delaware, not a swing state. Paul Ryan (Republican VP) was from the swing state of Wisconsin, though he was just a representative and thus was never elected by the state as a whole. Despite Ryan, Romney lost Wisconsin.
2008:
Biden as noted above was not from a swing state. Sarah Palin (Republican VP) was from Alaska, which was not a swing state due to heavily favoring Republicans.
2004:
This is a bit of an odd one. Up until now we've seen cases where a vice president is from a swing state or is from a non-swing state that strongly favors their party. But John Kerry chose John Edwards, a Democrat from the heavily Republican-leaning North Carolina, as his running mate. Now, starting with the 2008 election the presidential elections in North Carolina have all been fairly close (the largest win was when Trump won it by 3.76% in 2016, and the narrowest win was Obama winning by 0.32% in 2008), so it could be considered a swing state now. But this was back in 2004. Up until this point, Republicans won it every presidential election since 1980, including a killer showing in 2000 where they won by more than 13%. Perhaps Kerry thought that Edwards, who
had been elected to the Senate position in North Carolina in 1998 (Edwards didn't run for re-election due to focusing on his presidential bid, which he lost but did cause Kerry to choose him as VP), would allow him to win the state. It didn't work out, though, with Bush smashing Kerry in North Carolina 56.02% to 43.58%. As for the Republicans, Dick Cheney is from Wyoming, which is decidedly not a swing state, being one of the most staunch Republican states in the country.
2000:
We discussed Cheney above. Liebermann, the Democratic VP, was a Senator from Connecticut, which was not a swing state and is strongly Democrat.
So when we tally them all up, in 2000 through 2020, 9 of the 12 vice presidents were from states more or less guaranteed to go for their presidential candidate already. Vice presidents don't seem to be picked much for trying to "win over" their home state. And of the 3 that weren't, 2 of them were from states that the presidential candidate ended up losing (and for that matter, in
all 3 cases, they lost the overall election regardless of whether they won their state), so it doesn't seem to be a particularly effective campaign strategy.