The Third Way people can't: 1) explain what "extremism" is; 2) explain their position on NSPM-7, which similarly targets "extremism" that's poorly and broadly defined.
The "centrist" think tank Third Way is looking to pay someone between $140,000 and $150,000 to spend their days trying to dig up dirt on DSA members. They're trying to sell this gig as "anti-extremism" work, which I find completely disgusting.