Another thought after reading some more.
Carlson made some reasonable points, many I did not agree with but fair points. But as usual, he took it too far by concluding that this all means Tammy Duckworth hates America. This final conclusion is useful to agitate a disenfranchised base but is not truth. This idea that we love America because we are Republican and you hate America because you are liberal is exactly what turned me off to the Republican party years ago.
Now the other side can make the same mistake by saying Carlson is a racist because he doesn't believe we should take down a statue of Robert E. Lee. You can clearly say that Carlson is divisive for saying Duckworth hates America, that is clearly true, but as soon as you throw on the "he's racist" card, you are no better than the liberals hate America constituency (at least that is going to be the perception).
I guess the big difference is that Carlson might be racist (who am I to judge) but not simply because he wants to keep Confederate statues. When you throw that out there though, it is hard to back up. Everyone has a different idea. But there is no reality you can construct where Duckworth hates America just because she has different politics.