'come rain, blood, or horse manure' American idiom?

Question

Probably some of you, as I am, are familiar with the controversy that surrounded ABC miniseries Amerika (February 1987). ABC president response to that controversy was "we’re going to run that program come rain, blood, or horse manure." Surely he did not invent it on the spot; it must be an American saying or related to an American saying. However, my Google research came to no avail! So,

• Is "come rain, blood, or horse manure" an American saying?

• If so, what is its origin?

(Please edit-correct any grammar errors).

Answer 1

The line "come rain, blood, or horse manure" is but a colourful variant of the idiom

come rain or shine: no matter whether it rains or the sun shines; in any sort of weather

• Don't worry. I'll be there come rain or shine.

• We'll hold the picnic—rain or shine.

This one-off variant was coined by ABC president John B. Sias in 1987 after the yet-to-be-aired Amerika had generated more controversy and viewer response than any other ABC program in history, including The Day After. The miniseries took three years to make and cost nearly $40 million. The story was about the peaceful takeover of the United States by the Soviet Union with the complicity of international 'peacekeeping' troops, whose uniforms and insignia were similar to those of the U.N. forces.
_{Source: 'Amerika' Sponsor Chrysler Pulls Out. By New York Times}

The full quote is as follows

It will not cripple us. It'll hurt us. But we're going to run that program come rain, blood or horse manure.

Using Google's wildcard search, the Ngram shows that the version with rain, blood, or manure is not a common saying nor idiom.

However, if the OP is curious to know, the earliest instance of "rain or shine" I found on Google Books is dated 1822 in
The Edinburgh Review Or Critical Journal

He who, secure within, can say,
To-morrow do thy worst, for I have lived to-day.
"Be fair or foul, or rain or shine,
The joys I have possessed, in spite of fate, are mine;
Not Heav'n itself upon the past has power,
But what has been, has been, and I have had my hour."

Answer 2

I think the expression blood, rain, or horse manure is just a hyperbole used in that specific circumstance to strongly convey the idea that he was going to run the miniseries at any cost.

• an extravagant statement or figure of speech not intended to be taken literally, as “to wait an eternity.”.

Horse manure is used also metaphorically to indicate a nonsensical idea, but it is not related with the meaning used above.

• (euphemistic) if you describe something such as a statement or idea as horse manure, you are emphasizing that you think it is nonsense ⇒ 'Sounds like horse manure to me, Mikey boy,' said Ballpark., It's all a load of old horse manure. (Collins)

Horse manure: The Routledge Dictionary of Modern American Slang and Unconventional English.