Ten years ago today, then-Sen. Barack Obama of Illinois announced he was taking the first steps to run for president in 2008. In a three-minute video, he explained why — and what he hoped to accomplish.

It's remarkable as a historic artifact — God bless YouTube! — but if you watch the whole thing (it's only 187 seconds long!), you are reminded of the central reason Obama ran for president: to fix  broken politics.

Here's the key passage in Obama's exploratory committee announcement:

America's faced big problems before. But today our leaders in Washington seem incapable of working together in a practical, common-sense way. Politics has become so bitter and partisan, so gummed up by money and influence that we can't tackle the big problems that demand solutions. That's what we have to change first. We have to change our politics and come together around our common interests and concerns as Americans.

The big idea at the heart of Obama's candidacy was that he — because of his background, proven résumé and the historic nature of his candidacy — was uniquely suited to solve the partisan gridlock that had seized our politics under Presidents Bill Clinton and George W. Bush. That he could bring us all together through an appeal to our better angels and our shared values — and, in so doing, create a government that worked for all of us.

When he was elected in 2008, the coalition Obama built seemed to bear out that belief. He won New York and California, sure. But he also won North Carolina (the first Democrat to do so since 1976) and Indiana (first Democrat since 1964). Obama had, quite literally, changed the electoral map by convincing people that politics could be different and better.

Looking back now, Obama's announcement video feels almost quaint. An idealist promising something — changing politics — that was never going to happen. But in the months between that November election and Obama's inauguration in January 2009, there was a belief that we, as a country, might be on the verge of something new, different and better.

We were not. In fact, the election of Donald Trump as Obama's successor — someone who ran a campaign that, whether or not you agreed with him, never took the high road — would suggest a fundamental repudiation not only of Obama's promise to “fix” politics but also of the idea that people want politics to be “fixed” at all.

Why did Obama fail to reach the biggest goal he set out in that exploratory announcement a decade ago?

Democrats immediately point to the fact that congressional Republicans, almost from the first day of Obama's time in the White House, made opposing him a political strategy. “The single most important thing we want to achieve is for President Obama to be a one-term president,” Republican Senate Leader Mitch McConnell famously/infamously said in October 2010. That's a quote that many Democrats cite as evidence that Republicans never gave Obama a chance to make good on his grand vision of a better politics. If they wouldn't meet him 10 percent of the way, what realistic hope did he have?

Republicans place the blame on Obama, arguing that from the economic stimulus package to the Affordable Care Act and onward, he never had any real interest in working with them. Obama's promises to bring people of both partisan persuasions together was like lots and lots of his rhetoric as a candidate (and a president): It sounded good, but there was no action behind it. Deeds, not words, are what Republicans say they were looking for from Obama. And, they believe, they never came close to getting them.

Both views, to my mind, miss the point. And that point is this: There existed a chance for the president to make good on his most important campaign promise. That moment came in the summer of 2011 when Obama, House Speaker John A. Boehner and, on occasion, House Majority Leader Eric Cantor (Va.) huddled to work out the “grand bargain" — a massive package of debt and spending measures coupled with entitlement reforms that would have been one of the most monumental bipartisan deals ever crafted.

Obama wanted a tangible sign — as he prepared for his reelection race — that he could, as he had promised, bring the two parties together on something BIG. Boehner, who may have already seen the writing on the wall as the tea party began to rise against him, was in search of a career capper — something that he could point to and say, “I helped change the trajectory of our country.”

The pieces were in place. A deal seemed to be in the offing. And then it blew up.

Obama allies said Boehner just couldn't risk taking on the conservative wing of his party. Boehner allies said that Obama had reneged on key parts of the deal. Regardless of who was really to blame, that was the end of Obama's chances of making good on his promise of changing politics. The trust was gone between the two major players. And without trust you have nothing — in politics and in life.

Everything that followed from the collapse of the grand bargain — up to and including President-elect Trump — has taken us further from the place where our politics can be something new, different and better. The election of Trump — and the campaign he ran — also suggests that Obama's belief that people want a bigger and better politics may no longer hold true.

But as we prepare to move from one president to another very different president, it's worth remembering Obama's promise and the fact that for a brief moment in 2011 it actually looked achievable.