The Federation for American Immigration Reform (FAIR), a group that wants to reduce immigration to the United States and opposes the immigration reform bill that the Senate on Tuesday moved towards a full floor debate, is continuing to run TV ads this week in markets across the country.

The newest ad buy costs at least $36,525, based on records uploaded by broadcast TV stationsto a Federal Communications Commission website and available on Sunlight's Political Ad Sleuth. That follows a buy of at least $102,500 last week, records show.

These totals are likely low estimates, as the online posting is only a requirement in the country's 50 biggest TV markets, and only for stations in those markets that are affiliated with the nation's four major broadcast networks: ABC, CBS, Fox and NBC.

MORE: Sunlight resources for the immigration debate

This week's ads are running in Pittsburgh, Indianapolis, Charlotte, N.C. and Louisville, Ky., each of which saw FAIR ads last week too. The ads may be running in other cities but some stations are slower to upload the ad contracts on the Internet.

Last week's ad targeted senators in states from West Virginia to Ohio to Indiana, naming each state's senators. That ad focuses on the failed 1986 immigration overhaul, which promised to end illegal immigration, and asks viewers, "Shouldn't politicians make good on old promises before they make new ones?"

It's unclear if that ad is being used again this week. Paperwork for ad buys often show up before organizations post the advertisements, as is the case here. When asked about the content of the new round of ads, FAIR spokesperson Bob Dane wrote in an email: "We don't discuss the details of our ad buys."

Meanwhile, groups on the other side of the debate are purchasing air time as well. The Service Employees International Union launched a seven-figure national cable ad campaign through the end of June promoting immigration reform. Five separate ads, one of which is below, feature law enforcement officers, Republicans, small business owners, veterans, and so-called DREAMers, young people brought to the United States as children by parents who entered illegally and who are seeking an opportunity to stay in a country that, for many, is the only home they know.