The Republican ticket is flooding the airwaves with commercials that develop two themes designed to turn the presidential contest into a racially freighted resource competition pitting middle class white voters against the minority poor.

Ads that accuse President Obama of gutting the work requirements enacted in the 1996 welfare reform legislation present the first theme. Ads alleging that Obama has taken $716 billion from Medicare — a program serving an overwhelmingly white constituency — in order to provide health coverage to the heavily black and Hispanic poor deliver the second. The ads are meant to work together, to mutually reinforce each other’s claims.

The announcer in one of the Romney campaign’s TV ads focusing on welfare tells viewers:

In 1996, President Clinton and a bipartisan Congress helped end welfare as we know it by requiring work for welfare. But on July 12, President Obama quietly announced a plan to gut welfare reform by dropping the work requirement. Under Obama’s plan, you wouldn’t have to work and wouldn’t have to train for a job. They just send you a welfare check. And welfare-to-work goes back to being plain old welfare. Mitt Romney will restore the work requirement because it works.

The ad includes the following text and photograph:

Mitt Romney for President

Web sites devoted to examining the veracity of political commercials have sharply criticized the ad.

The Washington Post’s fact checker, Glenn Kessler, gave the welfare ads his lowest rating, four Pinocchios. The Tampa Bay Times’s Politifact was equally harsh, describing the ads as “a drastic distortion” warranting a “pants on fire” rating. The welfare commercial, according to Politifact, “inflames old resentments about able-bodied adults sitting around collecting public assistance.”

Sharp criticism has done nothing to hold back the Romney campaign from continuing its offensive — in speeches and on the air — because the accuracy of the ads is irrelevant as far as the Republican presidential ticket is concerned. The goal is not to make a legitimate critique, but to portray Obama as willing to give the “undeserving” poor government handouts at the expense of hardworking taxpayers.

Insofar as Romney can revive anti-welfare sentiments – which have been relatively quiescent since the enactment of the 1996 reforms – he may be able to increase voter motivation among whites whose enthusiasm for Romney has been dimmed by the barrage of Obama ads criticizing Bain Capital for firing workers and outsourcing jobs during Romney’s tenure as C.E.O. of the company.

The racial overtones of Romney’s welfare ads are relatively explicit. Romney’s Medicare ads are a bit more subtle.

“You paid into Medicare for years — every paycheck. Now when you need it, Obama has cut $716 billion from Medicare,” the ad begins, with following picture on the screen:

Mitt Romney for President

The ad continues:

Why? To pay for Obamacare. The money you paid for your guaranteed health care is going to a massive new government program that is not for you.

Mitt Romney for President

In essence, the ad is telling senior voters that the money they paid to insure their own access to Medicare after they turn 65 is going, instead, to pay for free health care for poor people who are younger than 65.

The Romney Medicare ads have a dual purpose. The first is to deflect the Obama campaign’s attack on the Romney-Ryan proposal to radically transform the way medical care for those over 65 is provided. The Associated Press succinctly described the Romney-Ryan proposal:

Starting in 2023, new retirees on the younger side of the line [those younger than 55 in 2012] would get a fixed amount of money from the government to pick either private health insurance or a federal plan modeled on Medicare.

Those going on Medicare after 2022 would have to choose between “premium support” — in other words, a voucher program — to pay for private health care coverage or an option to enroll in a program similar to existing Medicare but without specified funding levels — which means an end to the guaranteed medical coverage currently provided for those over 65.

The liberal Center on Budget and Policy Priorities sums up the likely future of health care for seniors under the Ryan proposal for reform:

The C.B.O. estimates that by 2030 the House Budget Committee plan would increase the out-of-pocket share of health care spending for a typical Medicare beneficiary from the current 25-to-30% range to 68%. By 2050, the House plan would cut federal health care spending by approximately two thirds. Both plans would place substantial administrative burdens on the most vulnerable and infirm of Medicare’s enrollees. And both would surrender the considerable leverage that Medicare can bring to bear on providers to reduce spending and improve quality.

Polls in key swing states and nationally show that, at present, voters trust Obama more than Romney to deal with Medicare, and strongly prefer to leave the Medicare program as is.

Asked whether “Medicare should continue as it is today” or “should be changed to a system in which the government would provide seniors with a fixed amount of money toward purchasing private health insurance or Medicare insurance” voters in Florida, Ohio and Wisconsin decisively chose to keep Medicare unchanged – by 62-28 in Florida, by 64-27 in Ohio, and by 59-32 in Wisconsin.

When asked whom they trust more to handle the Medicare issue, Florida voters in a Quinnipiac University/New York Times/CBS News poll, reported on August 23, picked Obama over Romney by a 50-42 margin. In Ohio, Obama’s margin was 51-41; in Wisconsin, it was 51-42.

A separate Pew Research Center survey released on August 21 found that 72 percent of voters had heard “a little” or “a lot” about what Pew described as “a proposal to change Medicare into a program that would give future participants a credit toward purchasing private health insurance coverage.” Of those familiar with the proposal, a plurality, 49 percent, opposed it, while 34 percent favored it.

The bipartisan Battleground Poll conducted August 5-9 by the Tarrance Group, a Republican firm, and Lake Research Partners, a Democratic firm, found that voters trusted Obama over Romney to handle Medicare and Social Security by a 49-45 margin. The same survey found that voters trusted Congressional Democrats over Congressional Republicans to handle Medicare and Social Security by a 48-40 margin.

Romney’s Medicare ad is designed to undermine that relatively modest but potentially crucial advantage. It is artfully constructed to turn the issue of health care into a battle over limited tax dollars between a largely white population of seniors on Medicare and a disproportionately minority population of the currently uninsured who would get health coverage under Obamacare.

Medicare recipients are overwhelmingly white, at 77 percent; 10 percent of recipients are black; and 8 percent Hispanic, with the rest described as coming from other races and ethnicities.

Obamacare, described in the Romney ad as a “massive new government program that is not for you,” would provide health coverage to a population of over 30 million that is not currently insured: 16.3 percent of this population is black; 30.7 percent is Hispanic; 5.2 percent is Asian-American; and 46.3 percent (less than half) is made up of non-Hispanic whites.

Politifact described the Medicare ad as “half true”:

Romney’s claim gives the impression that the law takes money that was already allocated to Medicare and funds the new health care law with it. In fact, the law uses a number of measures to try to reduce the rapid growth of future Medicare spending. Those savings are then used to offset costs created by the law — especially coverage for the uninsured — so that the overall law doesn’t add to the deficit. We rate his statement Half True.

Politifact also rated a claim Romney made later on the stump — that “there’s only one president that I know of in history that robbed Medicare, $716 billion to pay for a new risky program of his own that we call Obamacare” — as “mostly false.”

The Romney campaign’s shift of focus toward welfare and Medicare suggests that his strategists are worried that just disparaging Obama’s ability to deal with the struggling economy won’t be adequate to produce victory on November 6.

The importance to the Romney-Ryan ticket of two overlapping constituencies — whites without college degrees and white Medicare recipients — cannot be overestimated. Romney, continuing the Republican approach of 2010, is banking on a huge turnout among key white segments of the electorate in order to counter Obama’s strengths with minority voters as well as with young and unmarried female voters of all races.

There is extensive poll data showing the depth of Republican dependence on white voters.

On August 23, Pew Research released its latest findings on partisan identification, and the gains that the Republican Party has made among older and non-college whites since 2004 are remarkable.

Just eight years ago, Pew reports, whites 65 and over were evenly split in their allegiance, 46 percent Democratic, 46 percent Republican. In the most recent findings, these voters are now solidly in the Republican camp, 54-38, an eight point Republican gain. Elderly women were 9 points more Democratic than Republican in 2004, 50-41, the opposite of where they are now, 51-42 Republican. Older men, who were 51-41 Republican in 2004, are now 59-33 Republican.

Similarly, white voters without college degrees, of all ages, have gone from 51-40 Republican in 2004, to 54-37 in 2012, according to Pew.

Most importantly, the Pew surveys show that 89% of voters who identify themselves as Republican are white. Faced with few if any possibilities of making gains among blacks and Hispanics — whose support for Obama has remained strong — the Romney campaign has no other choice if the goal is to win but to adopt a strategy to drive up white turnout.

The Romney campaign is willing to disregard criticism concerning accuracy and veracity in favor of “blowing the dog whistle of racism” – resorting to a campaign appealing to racial symbols, images and issues in its bid to break the frustratingly persistent Obama lead in the polls, which has lasted for the past 10 months.

The result is a campaign run at two levels. On the trail, Paul Ryan argues that “we’re going to make this about ideas. We’re going to make this about a positive vision for the future.” On television and the Internet, however, the Romney campaign is clearly determined “to make this about” race, in the tradition of the notorious 1988 Republican Willie Horton ad, which described the rape of a white woman by a convicted African-American murderer released on furlough from a Massachusetts prison during the gubernatorial administration of Michael Dukakis and Jesse Helms’s equally infamous “White Hands” commercial, which depicted a white job applicant who “needed that job” but was rejected because “they had to give it to a minority.”

The longer campaigns go on, the nastier they get. Once unthinkable methods become conventional.

“You can tell they” — the welfare ads— “are landing punches,” Steven Law, president of the Republican super PAC American Crossroads, told the Wall Street Journal. Law’s focus group and polling research suggest that the theme is not necessarily going to work. “The economy is so lousy for middle-income Americans that the same people who chafe at the rise of welfare dependency under Obama don’t automatically default to a ‘get-a-job’ attitude — because they know there are no jobs.”

As the head of a tax-exempt 501(c)4 independent expenditure committee, Law cannot coordinate campaign strategy directly with the Romney campaign. Nonetheless, he is sending a warning. The welfare theme, Law said, “needs to be done sensitively. Right now it may be more of an economic issue than a values issue: In other words, more people on welfare is another disturbing symptom of Obama’s broken-down economy, rather than an indictment of those who are on welfare or the culture as a whole.”

Will the Romney campaign heed Law’s advice to keep it subtle? The principal media consultant for the pro-Romney super PAC Restore Our Future, which will be running many of the anti-Obama ads over the next ten weeks, is Larry McCarthy, who produced the original Willie Horton ad.

An earlier version of this column misstated the name of the newspaper that produces Politifact. It is the Tampa Bay Times, not the Tampa Bay Tribune.

Thomas B. Edsall, a professor of journalism at Columbia University, is the author of the book “The Age of Austerity: How Scarcity Will Remake American Politics,” which was published earlier this year.