He doesn’t want to stop it.
Obviously
Just last year, before the election, he stated that it was the law and it would be funded.
He still got re-elected and he still got re-elected as Speaker.
is there a primary challenger?......
Yes he does. Goodness...they’ve voted REPEATEDLY to end it...it is the SENATE that has refused to even ALLOW a vote on the many bills the HOUSE has passed.
A shutdown may be worse, because of what it does in the eyes of the public.
A denial of funding may be the better way, and I don’t know why he refuses to commit to that strategy.