On June 28, after roughly six weeks of intense debate, the immigration reform bill backed by the President and mostly Democratic Senators died an ignominious death on Capitol Hill. The next night on his CNN show, Lou Dobbs, one of the bill’s fiercest opponents, read congratulatory emails from viewers crediting him for defeating an “amnesty bill.”

That week, the last one in the second quarter of 2007, the immigration debate was the leading story at 12% of the newshole. Then, with the crusade over and legislative battle won, coverage plummeted.

The subject plunged to 2% of the newshole and ninth place on the top-story roster in July through September. That was down from 6% of the newshole and the fourth-leading overall story in the period from April through June. In the third quarter, immigration fell behind domestic terrorism, the Minnesota bridge collapse, the economy, tensions between the U.S. and Iran, and the Larry Craig scandal in the roster of big stories.

Coverage was down in every media sector from the second to third quarter: to 2% from 5% in newspapers, to 4% from 7% in cable, to 2% from 9% in radio, to 1% from 3% online, and to 1% from 4% in network TV.

On conservative talk radio, a subject that had been the No. 1 topic in the second quarter (at 16% of the airtime) fell all the way to 4% in the third quarter, as hosts picked up the slack with the Iraq debate, the presidential race and Senator Larry Craig’s arrest. On prime-time cable, the venue for hashing over the day’s hottest topics, it fell to 4% from 8%. And that’s despite the efforts of Dobbs who continued to hammer away at the issue.

According to the News Coverage Index, Dobbs alone was responsible for about one-third of all the immigration stories in the third quarter. That’s the main reason why CNN’s prime time cable coverage in the third quarter (7% and third-biggest story) continued to far outstrip MSNBC’s nighttime coverage (less than 1%) and Fox’s (4% and fourth biggest story).

Indeed, remove Dobbs from the equation and coverage of immigration on cable is halved—from 4% to 2%—in the period from July through September. Without Dobbs, it also falls to just 1% of the overall newshole for the third quarter.

Although immigration has been a sensitive political issue that worked its way into the presidential campaign (Hillary Clinton’s initial inability to deliver a clear position on a proposal to give drivers’ licenses to illegal immigrants was seen as a significant gaffe), media coverage has been uneven. The subject really caught fire when the fate of the legislation hung in the balance, but leveled off dramatically at other times. Despite that second quarter spike in coverage, the 2% of the newshole filled by the topic in the third quarter marked a return to the level of coverage (also 2%) that immigration attracted back in the first quarter.