Hmm. Never had to do that in Wisconsin or Michigan but apparently you do now. I was never in LA or IN more than the required days, so I don't know about those.
I doubt LA would have hit me anyway. I was there after Katrina helping out.
You possibly had to, and didn't know it. But because nobody was reporting your "WI/MI income" to their state tax authorities, they didn't know to come after you for it.
Maybe the infrastructure needed to seek out and hunt down every person who is in a state for a couple of days a year will cost more than they'll get in revenue, so they don't bother. But the revenue they'll get from pro athletes or major entertainers is high enough they DO spend that time.
There's a huge difference between taxing hotels-- which is really just a sales tax-- and taxing income, which is something historically done to residents. Residents who have the ability to vote to change the system, at least in theory.
And I'm certainly not suggesting it's unique to California. Google AI says it's common in many states. Obviously, since the mechanism for collection is the state income tax, it can only occur in states that have a state income tax. Take a look at that list, compared to the list of states with no income tax, and it's easy to see how this could become a political football. No pun intended.
Per the above, it'll only be a political football if they enforce it... You, Badge, and I have all traveled for work fairly extensively through our careers and have never even thought of it.
Just as technically, I have to report any out of state purchases that would be subject to California sales tax every year. Do I? Nope. In truth, that number is very nearly zero. But when we were all in Hawaii, the girls saw places like Louis Vuitton in Waikiki and were all joking that b/c sales tax is only 4%, it'd be financial malpractice
NOT to go spend a few thousand dollars on a handbag. (None of them did of course.)
Would I be worried that if we had bought a Louis Vuitton and brought it back to CA, that anyone from the state would show up at my door the following year wondering why I didn't pay CA sales tax on it? No. Because they can't track it.