Here's the actual story:
ap.google.com/article/ALeqM5h9G51QeAzd24Pf93rsKd9nRJzaogD90CAD900
I know Ronbo using the right words to describe thing isn't a reasonable expectation, but "tax evasion" isn't the right term here.
It appears that he paid income taxes on all of his income in his home state. Unfortunately, most states require that you pay taxes in their state on the income that you earn in that state. So, technically, if you travel to another state for business, you are supposed to pay taxes on that portion of your W-2 in that state. In reality, very few people do that.
It appears that he learned of those rules and then voluntarily filed the returns as required.
It should also be noted that he will now probably file amended returns in his home states (to the extent the statutes are still open) to claim credits for the taxes paid to the other states. If the statute has closed, he essentially ends up just being double taxed on that income.
I understand the desire to do the partisan dance and try to make a big deal out of this, but as someone who understands the complexity of the tax laws and knows how common this sort of thing is, and knows that people in this situation aren't "evading" taxes, I don't think it's really that big of a deal ... regardless of the political affiliation of the person.