Jim Messina, the campaign manager for Obama for America, wasn't mincing words Thursday morning.

In a fundraising email blasted out at 4:37 a.m., he said flat-out that GOP vice presidential nominee Paul Ryan "lied" about Medicare and the stimulus bill in his convention speech the night before.

Messina and the Democrats are zeroing in on two particular aspects of Ryan's 36-minute address, as Mitt Romney prepares for his own nomination address.

The first passage concerns what was once the largest employer in Ryan's hometown of Janesville, Wis.

"A lot of guys I went to high school with worked at that GM plant. Right there at that plant, candidate Obama said: 'I believe that if our government is there to support you, this plant will be here for another hundred years.' That's what he said in 2008. Well, as it turned out, that plant didn't last another year. It is locked up and empty to this day," Ryan said.

It is true that President Obama, when he was running for president in February 2008, toured the GM plant in Janesville. But Democrats point out that the plant actually closed in December of that year, under President George W. Bush -- who in that same month authorized an emergency loan of $14 billion to GM and Chrysler.

That was not enough to prevent GM from moving forward with plans it had already announced: to shutter the Janesville facility and lay off its remaining 1,200 workers.

His aides point out -- and GM confirms -- that the plant was not shut down per se but idled, meaning it could be reactivated at any time.

However, nothing Ryan said in his speech about the plant was factually untrue.

Ryan stated in his convention speech that "we were about to lose a major factory" in the town at the time Obama showed up there. And though he compressed then-Sen. Obama's remarks, Ryan did not distort them.

This is what Obama said at the time: "I believe that if our government is there to support you, and give you the assistance you need to re-tool and make this transition, that this plant will be here for another hundred years."

In October 2008, after the plant's fate was announced, then-Sen. Obama issued a statement that inched closer to promising to help the factory, which in its prime employed some 7,000 people. "As president, I will lead an effort to retool plants like the GM facility in Janesville so we can build the fuel-efficient cars of tomorrow and create good-paying jobs in Wisconsin and all across America," Obama said at the time.

The other part of the Ryan speech that Democrats are attacking is the passage concerning the so-called "Simpson-Bowles" commission, a bipartisan group empaneled two-and-a-half years ago by Obama to tackle the deficit.

Obama did not fully adopt the panel's recommendations, which included a mix of spending cuts and revenue enhancements -- otherwise known as tax hikes -- to put the country on a path to erase its now-$16 trillion debt.

"They came back with an urgent report. He thanks them, sent them on their way, and then did exactly nothing," Ryan said.

However, Ryan also served on that commission and opposed the final report.

Ryan aides explained Thursday the congressman partnered with a Democratic member of the panel, Clinton-era White House budget director Alice Rivlin, to address entitlement reform -- the real driver of U.S. debt -- and their plan was voted down by the commission. And that is why Ryan voted against the final recommendations, they said.

However, it was probably untrue for Ryan to say Obama "did nothing but dodge and demagogue this issue" -- as Obama put forth his own debt-reduction plan and did negotiate personally, albeit unsuccessfully, with House Speaker John Boehner.