By JIM RUTENBERG

Senator John McCain’s campaign began running this advertisement on Spanish language television stations in Colorado, Nevada and New Mexico over the weekend.

PRODUCER McCain media team.

SCRIPT (As translated by The New York Times) A male announcer says: “Obama and his allies in Congress say they are on the side of immigrants, but they’re not. Reports in the press say that their efforts were like ‘poison pills’ that caused immigration reform to fail. The results: ‘No’ to the guest workers program; ‘no’ to a path to citizenship, ‘no’ to secure borders. The reform didn’t pass. Is that being on our side? Obama and his Congressional allies — ready to block immigration reform, but not ready to govern.”

ON THE SCREEN The spot switches among montages of Mr. Obama and Senate Democrats — Harry Reid of Nevada; Patrick J. Leahy of Vermont — and Hispanic-looking voters and hazy images of federal buildings as onscreen writing flashes statements like “De Nuestro Lado?” ( “On our side?”).

ACCURACY The bill in question, which died in 2007, would have overhauled the nation’s immigration rules by creating a temporary worker program, a “pathway to citizenship” for illegal workers already here and provisions to tighten border security. Members of both parties took the blame for introducing amendments that ultimately killed the carefully developed compromise based upon an initial bill that Mr. McCain had helped draft. Before its fate was sealed, President Bush, who was pushing hard for its passage, directed much of his rhetoric against Republican opponents who dismissed it as “amnesty.”

Mr. Obama did support several Democratic provisions that were among those ultimately blamed for undermining it. He introduced an (ultimately losing) amendment curtailing a proposal to award green cards based on a point system that valued education and job skills more than mere family ties. And he joined with most of the Senate Democrats to support an amendment supported by labor groups and widely viewed as harming the bill by limiting the guest worker program at its core.

The key votes, however, came from four Republicans who initially voted against the amendment but switched sides at the 11th hour, they said, to destroy the broader bill. Mr. Obama did face some accusations of political expediency for siding with labor on a provision that was not favored by the Democrats who had forged the fragile, bipartisan compromise.

Still, after the bill’s failure, Senator Mel Martinez, Republican of Florida and a major backer of the bill, thanked Mr. Obama for his help, saying in a note that it “meant a lot to me personally.” And in May 2006, Mr. McCain complimented Mr. Obama for his “commitment to this issue,” and for “working to ensure this bill moved successfully intact through the legislative process.” Mr. McCain, however, said during a Republican primary debate in late January that if the legislation came back for a vote he would not support it because, “We know what the situation is today — people want the borders secured first.”

SCORECARD Mr. McCain was one of the more outspoken early voices for the liberalization of the immigration system, a fact he played down through the primary season that should now play well with Hispanic audiences. And any voters who carefully followed the debate would know that Mr. Obama was generally supportive of the legislation and that Republicans took much of the blame for its failure. Mr. McCain trails among traditionally Democratic-leaning Hispanic voters and his chances for victory will increase greatly if he can draw more of them into his column. But the spot could prove helpful to Mr. McCain among less informed, undecided Spanish-speaking voters looking for reasons to vote Republican this year.

JIM RUTENBERG