There exists a significant population in the USA who are very enthusiastic about a militarized force that functions to brutalize Black people.
This population likes seeing positive cases made for that sort of thing.
This creates a market.
The Times is a business.
If they wanted to report on the fact that a Senator was advocating horrors, they could have done that. Giving him space to make a positive case for horrors isn't a part of that.
They didn't offer Duterte a similar opportunity, for example.
It's that there's a market for Tom Cotton, and some businesses are quite willing to try to capture it.