She had power in MN, but had not become a "national" politician (yet).
I suspect that unless you live in New Mexico, you have no idea who the speaker of the NM House is. That's not a diminshment of the office or the person holding it, it's a recognition that while such positions come with significant power within the context of a state, they are quite hidden from residents of other states.
> Minnesota is part of Canada now? Must have missed that… :)
When you've dug yourself into a hole it's good idea to stop digging and get out instead of keep digging. As the GP pointed out, a US member of Congress refers to representative in the US Congress (that one from Washington, DC).
In addition to the US Congress, states have their legislative bodies. Melissa Hortman was a member of such a state legislative body -- the Minnesota House of Representatives.
So on one hand you sound like you know a lot about her and want her to be more well known, on the other hand you don't even know what legislative body she was a representative in. So that's pretty confusing.
For instance do you know Brandon Ler, the Montana House of Representatives speaker? Or, say, Nathaniel Ledbetter, the Alabama House of Representatives?
Are they "niche" politicians? In their states, no. But, absolutely yes when it comes to people from other states and more so from across the world.
It doesn't justify death, but it certainly makes it less surprising and more understandable.
Imagine if a democrat went into the deep south and said "The confederacy was a stupid joke you should be ashamed of, it only existed for 4 years, get rid of the flag already." etc etc and posted it to social media while talking over people trying to engage in debate.
Then that would be an apples-to-apples comparison. Not an elected representative.