The answer is simple. While the progressive marxists have been attacking America since Teddy Roosevelt’s day, and the attack is indeed multifaceted, two key items were needed to effect all the others. The progressive income tax to fund their activities and the effective takeover of the federal courts needed to protect the sedition and subversion. At least IMHO.
In Canada it all starts with the School Board Trustees (usually lawyers to boot)
They are bred and cultivated in the city schoolboards and graduated to City Politics. From there Provincial and Federal politics.
We keep worrying about the Federal Level when it really has to be addressed at the Education Level.