President Barack Obama will do more than try to heal the nation with his speech in Tucson, Ariz., tonight: He’ll try to recast his presidency and regain the trust of Americans who have lost faith in him over the past two years.

All eyes will be on Obama at 8 p.m. Eastern time as he addresses a memorial service at the University of Arizona for the victims of Saturday’s shooting rampage. White House aides say the president has been working on his remarks since Monday night and will devote much of them to honoring the victims.

“The president believes that right now the main thing we should be doing is offering our thoughts and prayers to those who’ve been impacted and making sure that we’re joining together and pulling together as a country,” White House spokesman Nick Shapiro said.

It’s a critical moment for Obama. Facing re-election in just two years, he has a narrow opportunity to prove he is the consensus-maker he promised he would be and win back the support of the public that elected him to the White House in 2008. His challenge is further heightened by a newly divided government — a GOP-controlled House — and a political landscape that many believe plays to the Republicans’ advantage in 2012.

Democratic Members and aides say they are looking for Obama to dig deeper and recapture the sense of shared purpose that existed on the day of his inauguration — something that has faded amid the vitriolic political climate that some argue contributed to Saturday’s violence.

Obama needs “to remind folks that we are all in this together — like he did during the campaign,” one senior Democratic aide said. “Everyone felt a sense of pride in how great America is. To some degree, this is his ‘standing on the rubble at ground zero’ moment.”

Rep. Gerry Connolly (D-Va.) said Obama should take a lesson from President Bill Clinton, who he said handled the aftermath of the Oklahoma City bombing with mastery. Many believe Clinton’s response to that tragedy helped ensure his re-election in 1996.

“We need less of the cerebral Obama and more of the visceral Obama,” Connolly said. “He needs to give us a Bill Clinton moment: I really do feel your pain.”

House Democrats also emphasized how crucial of a moment the tragedy is for Obama in terms of bringing people together.

“He needs to not miss this opportunity,” Rep. Debbie Wasserman Schultz said.

“Presidents have missed opportunities in the recent past to bring the country together,” the Florida Democrat said. “He needs to use the moment as a turning point.”

The White House has already demonstrated that it is taking Obama’s response to the attack seriously. Aides have sent out a steady stream of updates on the number of phone calls Obama has made to lawmakers and family members of victims of the shootings.

There have also been regular updates on the president’s numerous briefings on the status of the investigation. He publicly addressed the tragedy just hours after the shooting, canceled a scheduled trip to New York this week and immediately dispatched FBI Director Robert Mueller to Arizona to oversee the investigation.

Arguably the president’s toughest challenge is the reality that partisanship is alive and well on Capitol Hill.
“Democrats are looking for him to self-righteously spank the Republicans, and the Republicans are looking for him to say it isn’t their fault,” one senior Democratic aide said. “Can he walk the tightrope?”

One Senate Democratic aide summed up the conflicting feelings of some Democrats who want Obama to go after divisive political figures such as Sarah Palin and leaders of the tea party movement while simultaneously urging the country to tone down the partisan rhetoric.

“On the one hand, I want Palin to look fringe. I want Obama to show that he represents the country,” the aide said. “But on the other hand, if it looks in any way like he’s trying to politicize this, it will be a disaster.”

Another senior Democratic aide said Members are looking to Obama now more than ever to bridge partisan differences.

“Not just Members, but Americans, are looking for the president to rise to the occasion as he has in the past with the speech on race, for example, and they expect that he will,” the aide said.

Senior Republicans echoed the need for Obama to lead by example, but they speculated the Members on their side of the aisle will be looking more to their own party leaders for guidance.

“A lot of folks here in Congress will be looking to the Speaker — an institutionalist — more than the president for a steady hand,” one top GOP aide said.

“Instead of following the lead of some Congressional Democrats attempting to exploit this tragedy for legislative and political means, we expect the president to rise above them and use the bully pulpit to comfort the nation,” another senior GOP aide said.

Obama may have already helped to reset his presidency somewhat with the successes of the lame-duck Congress, during which he was able to deliver a few significant wins for his party, including a repeal of “don’t ask, don’t tell” and passage of the Strategic Arms Reduction Treaty. But as has been the case in the past with presidents faced with unimaginable tragedies, Obama’s biggest leadership test to date will arguably happen with tonight’s speech.

“He needs to show some emotion, pain, and reconnect with the American people on a deeply personal level,” a senior House Democratic aide said. “What I think he can do is reframe the debate and take some of the anger out of it and position those who seek to divide by using harsh and over-the-top rhetoric as counterproductive to the goals of America. He should remind folks that no single party is to blame here — we all can do better.”