The K of C can, and possibly should, oust any member who is not a practical Catholic according to their definition. This could possibly include a member who, as an example, is conspicuous by his regular absence from Sunday mass. The K of C does not conduct inquisitions to determine if each and every member lives in full compliance with all Church teachings, nor should it. For any action to be taken, the rejection of Church teaching would have to be public, as it was in the case of the Massachusetts politicians.
As to the charges of political activism by the Knights, there are numerous areas where moral and religious teaching and secular law overlap. As a Knight, as a Catholic, and as an active participant in all elections, I choose to follow the teachings of the Church first. If that spills over into influencing who I will vote for (or against) in an election, that’s the way it is and, in my opinion, the way it should be. The day the Knights quit being pro-life is the day I will resign. In the meantime, I’m all for giving the boot to any member, politician or not, who publicly defies Church teaching on abortion or any other major issue.