At an emotionally charged memorial service held in Arizona yesterday for victims of the Tucson shooting massacre, Barack Obama delivered a rousing speech to a 12,000 strong crowd that may be remembered as a watershed moment in the flailing President’s career.

Calling for calm and civility in the wake of the horrific incident in which a lone gun man killed six people and wounded 13 others in an assassination attempt on Democrats congresswomen Gabrielle Giffords, who is currently recovering in hospital after being shot in the head, Obama’s speech has generated widespread praise from both sides of politics as well as some inevitable criticism.

It provides a stark comparison to Sarah Palin’s divisive “blood libel” video address in which Palin earlier this week defended herself against accusations that provocative political rhetoric may have incited the Tuscon killings.

Here’s a small snippet from Obama’s speech (for a complete transcript, head here).

The truth is that none of us can know exactly what triggered this vicious attack. None of us can know with any certainty what might have stopped those shots from being fired, or what thoughts lurked in the inner recesses of a violent man’s mind.

So yes, we must examine all the facts behind this tragedy. We cannot and will not be passive in the face of such violence. We should be willing to challenge old assumptions in order to lessen the prospects of violence in the future.

But what we can’t do is use this tragedy as one more occasion to turn on one another. As we discuss these issues, let each of us do so with a good dose of humility

High profile conservative blogger Ed Morrissey was one of many staunch Obama critics who applauded the President’s address, calling it “what may be the finest moment of his presidency….he deserves credit and gratitude for his leadership at a point in time where the nation needed it, and I’m happy to give him both.”

Here’s a snapshot of what other commentators had to say:

The New York Times

Helene Cooper and Jeff Zeleny: Obama Calls for a New Era of Civility in U.S. Politics

It was one of the more powerful addresses that Mr. Obama has delivered as president, harnessing the emotion generated by the shock and loss from Saturday’s shootings to urge Americans “to expand our moral imaginations, to listen to each other more carefully” and to “remind ourselves of all the ways that our hopes and dreams are bound together.”

Financial Times

Richard McGregor:  Obama praised by left and right for Arizona tone

Mr Obama’s poll ratings, already climbing higher in the wake of a number of deals cut with the outgoing Congress in December, are expected to receive a further boost in coming weeks.

The Washington Post

Jennifer Rublin: Arizona memorial: It’s not about politics

As for the president’s speech, it was one of his better moments because it avoided politics.

New York Post

John Podhoretz: Prez perfect – but the crowd was appalling

Never before in the annals of national moments of mourning have the words spoken been so wildly mismatched by the spirit in which they were received.

The sentences and paragraphs of President Obama’s speech last night were beautiful and moving and powerful. But for the most part they didn’t quite transcend the wildly inappropriate setting in which he delivered them.

The New Republic

Jonathan Chait: Obama’s Moving But Ultimately Unsatisfying Speech

…overall, I’m not sure he quite managed the delicate balance the speech required. It felt to me like a speech that didn’t entirely transcend politics, but didn’t quite work as political rhetoric either.

The Daily Beast

Eleanor Clift: The Obama of Old Returns With Arizona Speech

Barack Obama found his voice Wednesday night, the one the country fell in love with in ’08. Gone was the stiff, sober professor, and here was the president we’ve been yearning for…

Lloyd Grove: Mourner-in-Chief’s Eulogy Puts Palin to Shame

Just on the level of majestic pageantry, it’s simply not possible for a Fox News commentator and TLC reality-show star to match the president of the United States and the Leader of the Free World. Palin was a rowboat to Obama’s aircraft carrier.

Kristen Powers: Obama Speech Missed an Opportunity

President Obama’s speech in Arizona was a huge missed opportunity. True, as always, he delivered as “Healer-in-Chief” and provided inspiration. This was Job 1 for the speech. But there was another job: shutting down the nonsense about how Sarah Palin or right-wing talkers caused the shooting.

The Telegraph

Toby Harnden: Barack Obama may have transformed his presidency

Barack Obama woke up at the White House on Thursday to a chorus from America’s political class hailing him as having transformed his presidency by delivering an artful and heartfelt speech in Tucson.

This was the response not just of Democrats or liberal reporters but also Mr Obama’s Republican opponents, who conceded that he had done himself a power of political good.

The Guardian

Jonathan Freedland: Barack Obama’s Tucson speech rose to the moment and transcended it

Throughout his presidency a doubt about Barack Obama has lingered, one that first surfaced during his campaign for the White House that began nearly four years ago. The fear was that – for all his oratorical brilliance – Obama somehow lacked empathy, that he was a slightly chilly, aloof figure, that he struggled to connect emotionally. We’ll hear much less of that talk now.