The first issue ad of the immigration reform battle hit the airwaves in South Carolina last week, targeting Sen. Lindsey Graham, R-S.C., who is up for reelection in 2014. NumbersUSA, one of the leading groups opposing comprehensive immigration reform paid for the ads, reports filed with the Federal Communication Commission show. The group, headed by long time advocate Roy Beck, has been around since the late '90s and argues that increased immigration will deplete the country’s resources, leading to sprawl, congestion and restrictions on individual liberties.

The new ad targets two key elements of the immigration debate, granting amnesty to the 11 million undocumented immigrants in the country and increasing the green card quota for those seeking to legally immigrate in the future.

The ad prods constituents to call Graham and tell him to oppose any such provisions. "Who elected Lindsey Graham to demand millions more immigrant workers when so many South Carolinians are jobless?" the ad questions. A spokesperson for NumbersUSA said that they are planning to run more ads in the future targeting both Democrats and Republicans. The current buy of radio and TV ads in South Carolina cost the group approximately $150,000.

The Sunlight Foundation’s site Ad Sleuth, which tracks political ad buys via reports filed with the Federal Communications Commission, surfaced the ad aimed at Graham. Because the ad does not tell voters to cast their ballots against the senator, NumbersUSA does not have to disclose the spending with the Federal Election Commission.

Graham is among the bipartisan group of Senators, known as the gang of eight, who have proposed an immigration reform measure. The plan puts undocumented immigrants on a path to citizenship while holding them accountable for taxes and fines due to the government.

Because he is the group's only Republican running for reelection next year, he's in the hot seat for groups opposed to the reform.

NumbersUSA is the most prolific spender among groups opposed to immigration reform. It has spent $910,000 lobbying on immigration issues in the last two years. And it might well have far more to spend in 2013 if the fundraising of its sister organizations are any indication: NumbersUSA Education and Research Foundation and NumbersUSA Action Inc., have a combined $6.54 million in the bank, their most recent tax disclosures filed in 2011 show.

Another source of ads that will oppose immigration reform plans is the Coalition of the Future American Worker, a network of organizations that includes NumbersUSA. This coalition has a few TV ready ads on their website, but haven’t made any ad buys that have been reported to the FCC yet. However, only the top 4 broadcast stations in the top 50 markets report ad buys to the FCC; if the coalition is running ads on cable or in smaller markets, their ad buys would not show up in Political Ad Sleuth.

On the pro-immigration side of the debate, Service Employees International Union has created a Spanish language ad, which is online only, asking people to call Congress next week to support a path to citizenship for undocumented immigrants.