President Barack Obama might  have handed Rep. Joe Sestak (D-Pa.) the issue he needs to win Pennsylvania’s Democratic Senate primary.

Sestak had been pulling ahead of Sen. Arlen Specter (D-Pa.) in recent polls, but Monday’s Supreme Court announcement might help put the congressman over the top.

The two-term congressman wasted no time in praising Elena Kagan’s nomination to the high court. And he also pointed out that the then-Republican Specter voted against her nomination as solicitor general when it came before the Senate Judiciary Committee last March.

{mosads}“I expect Sen. Specter may backtrack from his earlier vote on Ms. Kagan this week in order to help himself in the upcoming primary election, but the people of Pennsylvania have no way of knowing where he will stand after May 18,” Sestak said.

Specter issued a statement through his Senate office Monday saying he had an “open mind” about Kagan’s Supreme Court nomination.

“I have an open mind about her nomination and hope she will address important questions related to her position on matters such as executive power, warrantless wiretapping, a woman’s right to choose, voting rights and congressional power,” Specter said. “I voted against her for solicitor general because she wouldn’t answer basic questions about her standards for handling that job. It is a distinctly different position than that of a Supreme Court justice.”

Recent polls have shown Sestak closing the gap with Specter. On Friday, the Muhlenberg College/Morning Call tracking poll had the two tied at 43 percent. By Monday, the poll had Sestak ahead by five points — a margin also reflected in a Rasmussen Reports survey released the same day.

“The verdict was already out there; I just had to work hard” to get the message out, said Sestak.

“I’ve always said it was going to go down to the last week or two,” he said.

Sestak has long criticized Specter’s Republican past, and last week, he released his first TV ad on the topic, which featured footage of President George W. Bush calling Specter a “firm ally.”

Sestak’s other ads focused on his personal story.

Pollsters noticed the ad coincided with the shift in the race.

“The timing of our shift in the polls — the gain in Sestak’s number and the decline in Specter’s numbers — really did match up well with the issuing of that ad,” said Christopher Borick, director of the Muhlenberg College Institute of Public Opinion. “It doesn’t get much better in terms of a message to Democratic primary voters.”

But observers are waiting to see if Sestak has the campaign apparatus to get his supporters to the polls on May 18 and whether he can deliver a closing argument capable of sealing the deal.

Obama’s announcement on Kagan might have handed Sestak the initiative.

“The Supreme Court may well shape the character of America over the longer term [more] than maybe any institution in America,” he said. “And so therefore, I do intend to also speak about the qualities of Solicitor General Kagan.

“I think she’s a tremendous candidate.”

While Sestak pounds away on Specter’s Republican past, it’s the five-term incumbent who can count on the institutional support from Pennsylvania Democrats and their allies.

Rep. Chaka Fattah (D-Pa.) will urge his supporters in and around Philadelphia to get out in support of Specter, according to a spokeswoman for the congressman.

And an adviser to Ed Rendell (D) has said the governor stands ready to help rally his supporters in Eastern Pennsylvania.

“You’re going to see some of the party leadership from every corner of the state led by Gov. Ed Rendell and hopefully by our friends in the White House talking about why it’s important” to reelect Specter, Pennsylvania Democratic Party Chairman T.J. Rooney said recently.

The AFL-CIO is also planning a major push for Specter.

“We will be running our GOTV operation statewide for Specter and all the local candidates,” Eddie Vale, a spokesman for the union, told The Hill. “That’s canvassing, phone banking, work-site leafleting and turnout on Election Day.”

The White House has also been a powerful ally for Specter.

{mosads}Vice President Joe Biden campaigned with Specter in Scranton, and Obama raised money for him and recorded a radio ad that began airing last month. But it’s unclear what help the White House will provide in the final week of the campaign.

The announcement of Kagan’s appointment will undoubtedly occupy the majority of the political staff’s attention at a time when Specter needs it most.

A spokeswoman for the White House did not respond to a request for comment.