Last update: June 4, 6:40 p.m.

One week before the Senate is to begin debating a sweeping immigration reform bill that has bipartisan support, a leading opposition group is launching a multi-state ad buy, records in Political Ad Sleuth reveal.

UPDATE: The Federation for American Reform has spent at least $89,250 on TV buys in various markets this year, after TV stations posted more ad contracts Tuesday, according to a review of Ad Sleuth records (You can view all of the ad buys here). And in addition to the TV markets mentioned below, the group's ad is also airing in the Tampa, Fla. market.  

The ad takes aim at Marco Rubio, R-Fla., one of the Gang of Eight senators behind the bill and a potential 2016 presidential candidate, asking "Shouldn't politicians make good on old promises before making new ones?" while Rubio's face flashes on the screen. The ad harkens back to the 1986 immigration reform bill, which the ad's narrator says failed to deliver on its promises of improving border security, no amnesty for undocumented immigrants and reducing legal immigration. 

FAIR, which supports reduced immigration, has contracts to begin advertising Monday in a number of states that are home to potential swing votes on the bill. No one from FAIR has yet returned Sunlight's calls about them. But ad contracts show FAIR buying in in the Indianapolis, Ind., Pittsburgh, Louisville, Ky., Charlotte, N.C. and Cincinnati, Ohio markets during news programs. The buy at one station — WTHR, Indianapolis's NBC affiliate, was nearly $19,000. At a local ABC affiliate in Cincinnati, the buy was more than $14,000 and in Louisville and Pittsburgh, they were almost $7,000 each. The contract for the Charlotte station was not yet available on the Federal Communications Commission's website.

The numbers available likely understate the extent of the FAIR media buy because the FCC requires online disclosure of political advertising only by stations in the nation's top 50 markets and only by those that are affiliated with the broadcast networks ABC, CBS, Fox and NBC. Sunlight makes that information searchable and sortable on Political Ad Sleuth, a project of the Sunlight Foundation and Free Press. Interested parties can upload televsion ad information from stations and markets not covered by the FCC order. Information on how to participate in the project is available here.

FAIR's ad drop coincided with a Facebook campaign targeting senators in some of the states where the ads are airing. FAIR asks people to post on the Facebook walls of Minority Leader Mitch McConnell, R-Ky., who has said he will not block the bill, Sens. Richard Burr, R-N.C., Sherrod Brown, D-Ohio, Mary Landrieu, D-La., Mark Pryor, D-Ark., and Lisa Murkowski, R-Alaska. 

FAIR's advertisements represent the latest volley in a political air war that has begun to escalate in advance of next week's immigration debate in the Senate. Another group that opposes the legislation, NumbersUSA, made an 18-state buy last week. On the other side of the debate, the Service Employees International Union, made a national cable ad buy in support of the Senate bill last week.

In a blog post on FAIR's website, the group's president Dan Stein criticized the immigration legislation as having been "drafted in secret by eight senators and a group of Washington lobbyists" and said the legislation "received minimal scrutiny at a handful of hearings stacked with supporters of amnesty for illegal aliens and cheap labor for business interests."

The so-called Gang of Eight senators who shepherded the bill agreed to defeat any amendments that would derail the bill in an effort to preserve the fragile compromise they reached to push the bill out of Judiciary Committee and to the Senate floor.  The panel approved the bill on May 21.