According to a report posted online this morning, John McCain plans to name his running mate on Aug. 29, which happens to be his 72nd birthday — and, not coincidentally, the day after Barack Obama accepts the Democratic nomination.

The report, attributed to unnamed Republican sources by the Politico, emphasized the fact that McCain has kept virtually everyone in the dark about his choice, but referred to Gov. Tim Pawlenty and former Massachusetts Gov. Mitt Romney as “prime contenders.”

The report goes on to say:

The campaign has begun building a crowd of 10,000 for Dayton, Ohio, according to an organizer. McCain is scheduled to appear with his running mate at a large-scale event in Pennsylvania shortly thereafter.

Senior Republicans are in the dark about who he’ll name, although they say former Massachusetts Gov. Mitt Romney and Minnesota Gov. Tim Pawlenty are prime contenders after a trial balloon by McCain gave him very negative feedback about the idea of picking an abortion-rights running mate such as Tom Ridge, the former governor of Pennsylvania and the first secretary of homeland security.

Sources close to McCain say he has wrestled with the choice, torn between a high-stakes, high-reward pick like Ridge or Connecticut Sen. Joseph I. Lieberman — the Democratic vice presidential nominee in 2000 — or a safer and more conventional selection such as Romney or Pawlenty….

The announcement strategy — provided McCain doesn’t change it — calls for naming the pick early Friday morning to try to suppress Obama’s bounce coming out of his convention.

“You’re going to own the weekend,” a McCain official said.

The Republican convention begins the following Monday — Labor Day — in St. Paul, Minn.

Update: More tea-leaf reading on the veepstakes, courtesy of MSNBC’s Chuck Todd:

“The growing Republican CW is twofold. One, Pawlenty appears to be the safest pick, given that one no one is vetoing him. And two, McCain is more likely than Obama to upend the CW with his decision.”

Later update: The Associated Press is reporting that Pawlenty is heading back on the road to stump for McCain.

Prospective vice presidential candidate Tim Pawlenty is gearing up for a weekend campaign swing in Ohio and Pennsylvania on behalf of Republican John McCain.

Minnesota’s GOP governor says he’s heading to the two important battleground states to give speeches and rally McCain supporters. Pawlenty has been on the road for McCain much of the summer, including Monday in Wisconsin.

He refuses to answer questions about his possible place on McCain’s ticket. Pawlenty says he might travel to Denver next week as a McCain surrogate during the Democratic National Convention. No details on that trip have been firmed up.

In the doldrums of August, with John McCain dominating the current news cycle while Barack Obama wraps up his vacation in Hawaii, both campaigns have been stepping up their attack ads.

McCain’s most recent dumps the Paris Hilton references, but keeps alive his campaign’s “mere celebrity” rap on Obama in his new “Taxman” ad:

Obama’s ad, “Fix the Economy,” uses McCain’s own words against him, pairing his recent sunny assessments of the economy with fear- and despair-filled words of voters:

On an unrelated note, both candidates will stage their first joint appearance of the campaign on Saturday when they travel to California for an appearance at the Rev. Rick Warren’s Saddleback megachurch. Matthew 25, a pro-Obama Christian group that hopes to enlist religious voters for the Democratic candidate, will air an ad called “Families” during the televised confab:

None too pleased about John McCain’s “Celeb” ad that has largely defined the campaign this week, the Democratic National Committee has fired back with this ad:

Figuring their first shot at least drew blood, McCain’s ad shop came back with more mockery of Obama, in an ad called “The One” (the snark nickname McCain staffers have long used for Obama).

Team Obama promptly let it be known it was shocked, shocked: “It’s downright sad that on a day when we learned that 51,000 Americans lost their jobs, a candidate for the presidency is spending all of his time and the powerful platform he has on these sorts of juvenile antics,” said spokesman Hari Sevugan.

While the breathless speculation about Vice President Tim Pawlenty has largely quieted as the week has wound down considerably, his immediate travel plans have kept the veep buzz alive.

On Saturday, he’ll be campaigning in Iowa, at the invitation of the state GOP. Come Monday, he’ll be in Ft. Sill, Oklahoma, for a send-off for Minnesota National Guard troops who are headed for Iraq (great photo op, guv!). Then, apparently after a day back in Minnesota, he’s headlining at the National Press Club in Washington, D.C., on Wednesday.

Also, the Strib archives show that before there was vice-presidential buzz about Pawlenty, there was presidential buzz about him.

In early 2005, in the wake of President Bush’s re-election, his name was already in play, bigtime:

His national name recognition probably doesn’t exceed 5 percent,
but in recent conversations about possible 2008 presidential candidates, Gov. Tim Pawlenty was mentioned more favorably by top conservative Republican leaders meeting in Florida than such household names as Rudolph Giuliani and John McCain.

Just Friday, the New York Times named him “a popular conservative considered a rising star.”

Grover Norquist, another top GOP architect who heads the group Americans for Tax Reform, said Pawlenty has caught the eye of elite conservative decision makers. “A successful governor who doesn’t raise taxes, passes concealed carry, reins in spending and who comes from a blue state that’s trending Republican is an attractive candidate for president or vice president.”

“Of the guys in the top 12 for `08, he’s right up there,” Norquist said.

(…snip)

“There’s an undercurrent of talk all the time about Pawlenty,” said Vin Weber, a former congressman, a top Republican strategist and a Washington lobbyist.

During presidential inauguration week in January, Pawlenty was one of the most sought-after interviewees by conservative opinion leaders from George Will to Charles Krauthammer, says GOP Chairman Ron Eibensteiner. He’s constantly getting requests from all over the country to speak at political and public policy events.

Paul Weyrich, an influential conservative who founded the Heritage Foundation and has strong ties to the White House, said that of the candidates who appeal to the Republican base, “I would rank Tim Pawlenty fairly high - in the top three or four nationally.”