TV viewers may be undecided about how they will vote in the upcoming presidential election, but if Wal-Mart has its way, they should not be undecided about where to shop.

As the Democratic and Republican National Conventions get underway, Wal-Mart is preparing to launch a series of TV ads that will highlight how consumers, worried about the economic climate, can save money by shopping at the discount retailer.

The ads will run on cable news networks like CNN and MSNBC during the Democratic National Convention in Denver, Colorado, and the Republican National Convention in St. Paul, Minn. The ads will start on Aug. 25 and run through Sept. 7.

In rolling out the ads, Wal-Mart cited a survey by Voter/Consumer Research of Washington, DC according to which more than half of all Americans surveyed – including three quarters of African-Americans and about two thirds of Hispanics — said they are more likely to shop at Walmart discount stores now compared with six months ago. It also said that nearly half of registered voters who are currently undecided between presidential candidates Sen. Barack Obama and Sen. John McCain say they are more likely to shop at Walmart today than they were six months ago.

“Americans are facing unprecedented financial challenges and we see them in our stores every day — working men and women living paycheck to paycheck and faced with difficult decisions,” said Walmart U.S. CEO Eduardo Castro-Wright in a statement. “… This new advertising campaign reinforces that we will continue to be there for them.”

The ads will highlight Wal-Mart’s $4 generic prescription drug program, which it says has saved Americans an estimated $1 billion. It will also tout how consumers can save money and gas by taking a one-stop shopping trip to its stores.

It is an interesting time for Wal-Mart to link itself with the presidential election. 

Labor groups have asked federal regulators to look into whether Wal-Mart broke the law during company meetings with store managers where it warned about the consequences of a proposed labor law backed by Democrats. At issue is whether Wal-Mart’s discussion of the law, which would make it easier for workers to unionize, amounted to an effort to dissuade employees from voting for Obama.

Wal-Mart denies that it tried to influence voting.

(Graphic provided by Wal-Mart from the ad campaign)