This fall’s gubernatorial race and battle for control of the state Legislature could be dominated by substantive and worthwhile discussion about the state’s most pressing challenges — how to reshape Maine’s economy and position it for growth in the 21st century, for instance. Instead, the Maine Republican Party and those supporting Republican candidates have zeroed in on fear and simplicity in order to turn out votes for Gov. Paul LePage and against Democratic candidates. Their target of choice is “illegal immigrants.”

“Do you think Maine’s cities and towns should continue to use your tax dollars to pay welfare benefits to illegal immigrants?” asks one ad produced by the Republican Governors Association that shows dark, sinister-looking images supposedly of people who have crossed the border and come to Maine illegally. “Mike Michaud does.”

Beyond the looseness with the truth and the demonization of a group of people (“illegals”), what’s most offensive about the ad — and the overall push to use public assistance for undocumented immigrants as a wedge issue this campaign season — is the oversimplification of a complicated issue that has no place at the top of any list of most pressing challenges for Maine to confront.

What’s at issue are the small allotments of last-resort, emergency aid that municipal governments issue to people in need — most of whom need it to pay their rent or heating bills. The benefits, issued through General Assistance, are a combination of state and local funds.

Altogether, General Assistance amounts to about $12 million annually in state funds in the context of a $3 billion state budget. That’s less than one half of 1 percent.

But based on the rhetoric, you might expect General Assistance to be among the top line items blowing a hole in the state budget. And it might seem as if Maine is overrun with undocumented immigrants who are bilking the system. (In truth, it’s notoriously difficult to measure undocumented immigrant populations, but Maine’s is so small, it can’t be reliably measured.)

If the LePage administration successfully manages to cut off the small portion of that sum making its way into the hands of people who can’t prove they’re in this country legally — but who could very well have good and legal reason to be here — the savings to the state are likely to be miniscule, if they present themselves at all.

That’s because, in order to cut off General Assistance benefits just to undocumented immigrants, towns and cities need to affirm the immigration status of every applicant for General Assistance in order to avoid breaking federal equal protection laws. That’s not a simple matter, and it’s fraught with legal risk.

“Suffice it to say that any municipality embarking on such an endeavor will be taking on significant liability and administrative burden,” warns a General Assistance manual prepared a decade ago by the state Department of Health and Human Services and a handful of local officials.

That administrative burden costs taxpayers money — at both the local and state levels. If local officials can’t affirm an applicant’s immigration status, DHHS has instructed them to consult the state for help.

And the additional administrative burden isn’t the only added cost. Consider the cost to the state of hiring a private attorney to fight a legal battle over this issue in court with the Maine Municipal Association, the American Civil Liberties Union of Maine and the cities of Portland and Westbrook.

The Maine GOP’s fundraising appeal is correct in that this is a fight about “how our tax dollars will be used.” Under LePage’s stigmatizing, anti-immigrant General Assistance directive, it’s clear that taxpayer dollars are not being used efficiently or for maximum benefit and that real people, not dark figures in a TV ad, will be hurt.