The Liberals wanted Poilievre legally silenced because his arguments were winning against the Liberal talking points. So if he is now forced to stay silent then that allows the Liberals to lie to the people, lie to the public, and Poilievre can't explain why what they are saying is false. But with him not getting security clearance he can point out falasies in their statements and argue against their logic and there is no legal danger for anything he says because he has not seen anything.

If Poilievre sees some secret information and fires a member of his own Conservative party that is mentioned in the information, Poilievre violated the security act and legally he's out. Without that security clearance he has full reign as leader without confines or legal restrictions.

He rejected the security clearance because if he mentions anything they show him he can be charged criminally on national scecurity grounds, even as a sitting member of parliment he can be charged and his seat would be in jeopardy if he talks.

The Liberals push for him to get a security clearance was all a tactic to force him into silence under threat of arrest if he mentions what he reads or sees.

Poilievre cannot be defeated if you attack him from the left. Everything from legacy media is to the left. Poilievre very much can be defeated if you hit him from the right.