Why did CO, MN, and NH have such strong leftward swings?

[Kamala's side hoe]

Also, why did PA, MI, and WI have much smaller swings?

Colorado, Minnesota, and New Hampshire all have 3 of the largest moderate populations in the united states, and some of the smallest proportions of the population that identify as conservative. As Biden did extremely well with moderates, it makes sense that the largest swings occurred in places such as New Hampshire, Colorado, Minnesota, Oregon, and Virginia, that have large portions of college-educated moderate voters.

That source says HI, DE, RI, ND, and UT have even higher percentages of self-identified moderates. None of CO, MI, NH, or OR are >40% "moderate", but their "moderates" are probably more likely to be socially liberal, college-educated white people than elsewhere.

[Kamala's side hoe]

Also, why did PA, MI, and WI have much smaller swings?

Colorado, Minnesota, and New Hampshire all have 3 of the largest moderate populations in the united states, and some of the smallest proportions of the population that identify as conservative. As Biden did extremely well with moderates, it makes sense that the largest swings occurred in places such as New Hampshire, Colorado, Minnesota, Oregon, and Virginia, that have large portions of college-educated moderate voters.

That source says HI, DE, RI, ND, and UT have even higher percentages of self-identified moderates. None of CO, MI, NH, or OR are >40% "moderate", but their "moderates" are probably more likely to be socially liberal, college-educated white people than elsewhere.

The 2nd part is just as important as the first. Utah and North Dakota have well over the national average for percentage of population that is conservative, and Delaware/Rhode Island/Hawaii all rank towards the bottom in the same metric.

Not sure about Delaware or Rhode Island, but I'm guessing the 40% of "moderates" in Utah are more likely to be libertarian/Never-Trumpist types, while the 45% of "moderates" in Hawai'i are more likely to be apolitical, communitarian types.