Campaigning in Iowa today, Mitt Romney took a relatively new tack in going after President Obama, characterizing the president as having promised to be a savior to the entire planet.

“I’ve been watching some clips of President Obama, then candidate Obama, when he was going across Iowa four years ago,” Romney said. “And the promises were just non-stop of all the great thing he was going to do: heal the nation, bring us together, repair the nation and repair the world.”

I watched the 2008 race pretty closely, and I’m fairly certain Obama never promised he’d single-handedly “repair the world.” What’s more likely is that Romney, an enthusiast of “post-truth politics,” simply made this up. He does that a lot.

But as lies go, this one is fairly important because of what it tells us about the larger Republican strategy. Peter Wallsten has a good piece today on the literal GOP playbook.

With Republican voters in Iowa set to finally begin picking a nominee to challenge President Obama, GOP officials in Washington are quietly and methodically finishing what operatives are calling “the book” — 500 pages of Obama quotes and video links that will form the backbone of the party’s attack strategy against the president leading up to Election Day 2012.

The document, portions of which were reviewed by The Washington Post, lays out how GOP officials plan to use Obama’s words and voice as they build an argument for his defeat: that he made specific promises and entered office with lofty expectations and has failed to deliver on both.

Not surprisingly, I happen to think the GOP officials are wrong, and that the president has kept his promises and had extraordinary successes under nearly impossible circumstances. Some of the promises Obama made four years ago were no doubt scuttled by the global economic crash — which came nine months after the 2008 Iowa caucuses and five months before Obama took the oath of office — but sane voters should realize that campaign pledges made a year in advance had to adapt to radically changing circumstances.

The more interesting point here seems to be the part about “lofty expectations,” which Romney alluded to with his “bring us together” comments this morning.

It’s not unreasonable to look back and recognize that Obama, as a candidate, really did have grand ambitions about changing politics and improving the way policymakers approached problem-solving. He also came into office at a time of remarkable crises — I’d argue no president since Lincoln took office and faced the kind of challenges Obama did — and sincerely hoped well-intentioned officials on both sides of the aisle would be willing to do the right thing, regardless of party.

Three years later, did the president help usher in a “post-partisan” era? Of course not. And if Republicans are successful, voters who expected otherwise may take out their disappointments on the incumbent president.

But here’s hoping sensible voters pause to consider why political conditions deteriorated as they did. Greg Sargent had an important piece on this earlier today.

…Obama had barely been sworn into office before the national Republican leadership mounted a concerted and determined effort to prevent any of Obama’s solutions to our severe national problems from passing, even as they openly declared they were doing so only to destroy him politically. Republicans have admitted on the record that deliberately denying Obama any bipartisan support for, well, anything at all was absolutely crucial to prevent voters from concluding that Obama had successfully forged ideological common ground over the way out of the myriad disasters Obama inherited from them. […]

[A]s Steve Kornacki recently noted, blaming Obama for failing to transcend politics as usual despite determined GOP opposition may be the best way to give indys and moderates a reason to vote against Obama even though they generally agree and sympathize with him. And so, after doing everything in their power to prevent Obama from successfully transcending partisanship and achieving transformative change — even if it meant repeatedly opposing solutions to profound national problems they once embraced — Republicans will now attack him for failing to transcend partisanship and achieve transformative change.

Greg posted that at 9:13 this morning. Before lunch, Romney had already proved him right.

Steve Benen

Follow Steve on Twitter @stevebenen. Steve Benen is a producer at MSNBC's The Rachel Maddow Show. He was the principal contributor to the Washington Monthly's Political Animal blog from August 2008 until January 2012.