Many different kinds of organizations are organized as corporations. Charities, newspapers, churches, etc. If the amendment was not carefully written, it could be construed to deny important rights, such as press freedom or religious freedom, to organizations that really ought to be protected. Similarly, the protections against unwarranted search and seizure or taking of property for pubic use without compensation should probably continue to cover corporations.

Really, the only problem I see WRT corporations having constitutional rights is the decision that political spending is protected speech. The other constitutional rights are generally not problematic.

So maybe something like this:

1. No person, whether natural born human or legal fiction, shall spend, donate, or otherwise make valuable contributions to any candidate or campaign, if said person is not entitled to vote in the election for such candidate or campaign.

2. Only natural born human beings shall be entitled to vote in any election.