If we want to have artificially-generated demand for zinc – if we really need to ensure domestic production capacity – there’s no requirement for it to be the penny. I’m sure that we can find something else to make out of zinc.

The penny itself wasn’t always zinc. I don’t remember the changeover year.

checks WP

https://en.wikipedia.org/wiki/Penny_(United_States_coin)

The current copper-plated zinc cent issued since 1982 weighs 2.5 grams, while the previous 95% copper cent still found in circulation weighed 3.11 g (see further below).

https://en.wikipedia.org/wiki/Zinc

Zinc is most commonly used as an anti-corrosion agent,[123] and galvanization (coating of iron or steel) is the most familiar form. In 2009 in the United States, 55% or 893,000 tons of the zinc metal was used for galvanization.[122]

Zinc is more reactive than iron or steel and thus will attract almost all local oxidation until it completely corrodes away.

We can just subsidize zinc production, or purchase something that requires those anti-corrosion properties.

I also am not at all sure that this was in fact the rationale. I can’t find a reference online to this being the rationale. I do see reference to zinc being useful because it’s particularly inexpensive. And the numbers given on this article seem to support the idea that pennies don’t really work out to generating a very substantial demand for zinc.

https://www.forbes.com/sites/timworstall/2015/01/03/its-not-big-zinc-behind-the-campaign-to-keep-the-penny/

It’s Not Big Zinc Behind The Campaign To Keep The Penny

To run through the numbers, a penny coin weighs 2.5 grammes. Let’s call that all zinc (it’s not, but close enough). There’s 5 billion made a year, meaning that we’ve got 12,500,000,000 grammes, or divide by a million to get 12,500 tonnes. Now, if that were 12,500 tonnes of gold being made into coins every year, with global virgin production being around 3,000 tonnes, then sure, that would be a contract worth, umm, influencing the political process, to secure and keep running. The same would be true of many metals in fact. But it’s just not true of the zinc industry. Using the USGS, the correct source for these sorts of numbers, we find that US production of zinc is around 250,000 tonnes a year, global production 13.5 million. Even if we assume (as we might, sounds like the sort of thing that might be true) that US coins must be made of US produced metal this is still a very marginal part of the total market.

Further, zinc runs about $2,200 a tonne at present, meaning that we’re talking about maybe $25 million a year as the zinc cost of our pennies. And we’re told who and how much is paid to keep lobbying for the penny:

But his written statement did not mention that Weller is actually a lobbyist and head of strategic communications for Dentons, a law firm representing the interests of zinc producer Jarden Zinc Products, a major provider of coin blanks that are made into currency.
…
Jarden Zinc Products spent $1.5 million from 2006 through the first quarter of 2014 lobbying on such things as “issues related to the one-cent coin” and represented by Weller when he worked at B&D Consulting and, more recently, Dentons.

No, the important point here is not the zinc industry, nor “Big Zinc”. The important part is this “a major provider of coin blanks”. If your business is making coin blanks then obviously you’re very interested in the continued existence of coin demoninations that are made from coin blanks. That they’re made from zinc is an irrelevance compared to that.

Believe me, you don’t spend the best part of $200,000 a year in lobbying expenses in order to sell $25 million’s worth of zinc. This metal is a commodity, you can sell that amount in one ten minute phone call to any London Metals Exchange ring member. Heck, give me a couple of days to get organised and I could sell it for you at the market price. I’d also charge rather less than $200,000 to do it.

EDIT: WP seems to also support the author’s argument.

https://en.wikipedia.org/wiki/Jarden_Zinc_Products

The company has resisted past efforts to eliminate the penny in the United [1] through an astroturf lobby organization called Americans for Common Cents.

The company’s largest source of revenue comes from the production of coin blanks, having produced over 300 billion blanks at their Tennessee facility.