The 2012 presidential campaign finally captured some media attention last week, the Pew Research Center's News Coverage Index reports.

The primary reason? Donald Trump.

The Pew Center's News Coverage Index every week tracks which stories the press is covering. Here's an excerpt from a report on last week's numbers:

For the week of April 18-24, the 2012 presidential race emerged as a big story, more than doubling its previous high water mark this year. It accounted for 8 percent of the newshole studied by the Pew Research Center's Project for Excellence in Journalism, making it the third-biggest story in the news last week. And a closely related story (at 3 percent) involved attention to Obama himself, with a particular focus on the "birther" movement that questions whether the president was born in the U.S.

In both cases, that was due in large part to the attention garnered by real estate developer, reality TV star and now possible presidential candidate Trump -- who has embraced the birther issue and become the rising star of the GOP presidential field.

Indeed, Trump was the week's second leading newsmaker behind Obama, registering as a dominant figure in 4 percent of all the week's stories. That is six times more attention than the next most-covered potential GOP contender, Sarah Palin, generated last week.

Also in the Pew report:

For a number of reasons, including that fact that there is an incumbent seeking re-election, coverage of the 2012 presidential campaign has gotten off to a slower start than the 2008 race. (So far this year, it has accounted for only 2 percent of the newshole compared with 7 percent at the same point four years ago.)

But that began to change last week as the race took root in the cable news sector, which is most attuned to politics and partisan controversy. (The campaign was the No. 1 story in cable last week, filling 19 percent of the airtime studied. In stark contrast, it accounted for only 2 percent of the front-page newspaper coverage examined by PEJ.)

There were several news-making developments last week, including the entry of long shot libertarian-leaning Gary Johnson, the former governor of New Mexico, into the Republican race. And there was a drop in Obama's approval ratings that got some attention.

But the real attraction was Trump, who has jumped to the top of some GOP polls with a campaign that has thus far focused on Obama's birthplace and blunt talk about getting tough with China and seizing Middle Eastern oil fields. If Trump's sweeping policy positions and birther mantra are raising eyebrows about his seriousness as a candidate, the media last week seemed primarily respectful of his ability to so quickly inject himself into the race.

Trump's comments weren't the subject of a single news story in the St. Louis Post-Dispatch during the week surveyed by the News Coverage Index. But his potential candidacy was featured or mentioned in five commentaries on the Other Views page. (For newspapers, the New Coverage Index only includes news stories that start on the front page.)

On Monday, Trump introduced another hot topic during an interview with Beth Fouhy of the Associated Press. Trump said that he heard that Obama was a "terrible student" who didn't deserve to be admitted to an Ivy League school.

Trump told Fouhy: "I heard he was a terrible student, terrible. How does a bad student go to Columbia and then to Harvard? I'm thinking about it, I'm certainly looking into it. Let him show his records."

Fouhy writes:

Obama graduated from Columbia University in New York in 1983 with a degree in political science after transferring from Occidental College in California. He went on to Harvard Law School, where he graduated magna cum laude 1991 and was the first black president of the Harvard Law Review.

Obama's 2008 campaign did not release his college transcripts, and in his best-selling memoir, "Dreams From My Father," Obama indicated he hadn't always been an academic star. Trump told the AP that Obama's refusal to release his college grades were part of a pattern of concealing information about himself.