Who can crack this Miscellany mystery?

This is a letter (with enclosure) that seems to reveal a plot against Rev. William Thomas Walker (1844-1895), a Disciples of Christ minister in Caswell County who ran for governor on the Prohibitionist Party ticket. Was Walker blackmailed? For what purpose? Did the doctor agree to attest to Walker’s opiate-induced stupor?

Can’t swear to the accuracy of my transcription, but I think I captured the gist. The letter is now in the collection, if anybody wants a first-hand examination.

Greensboro N.C. June 16 — 88

Dear —,

The importance of securing the signature of Dr. W.A. Drury [?] to a testimonial, a copy of which I herewith inclose, or something similar thereto, cannot be overestimated. For you can then write the communication and back it up with Dr. Drury’s affadavit. Of course it is not necessary for the affadavit to be published, and you can so state to Dr. Drury, but you may want it held in reserve to substantiate the charge after it appears, but I have no idea really that any of his friends will attempt a denial of the charge.

You re-write the affadavit or testimonial I send herewith before presenting it to Dr. Drury so that he will not detect my hand. Write me at once.

Frank [?] Whitehead
Brown’s Summit,N.C.

June — 1888

I hereby certify that I was called to see one Mr. W. T. Walker, the present candidate for Governor on the Third party ticket about [blank] years ago on a professional call to administer physic to a man who had taken laudanum for whiskey. Upon my arrival Mr. Walker stated without soliticitation on my part, that he had mistaken a bottle of laudanum for a bottle of whiskey that was in his valise and requested me to do something for him and do it quick. I administered physic to the afflicted man and had two men to walk him all night to keep him from going to sleep, one on each side. By this means his life was prolonged….

Mr. Walker stated that he regretted the circumstances on account of his family as much as anything else, remarking that they would certainly find it out. I prefer not to go any further into the details of the matter.