The Des Moines Register has endorsed Barack Obama today, joining the Charlotte Observer, the Baltimore Sun, the Ft. Worth Star-Telegram, and the Hartford Courant, whose editorial board has endorsed a Democratic candidate only twice in 244 years.

The DMR endorsement is oddly enough based on something McCain’s campaign has been touting for two years: being tested. Despite endorsing McCain last December as the Republican nominee, the DMR believes that Barack Obama has made it through many hoops in Iowa, such as winning the Iowa caucus.

From the DMR:

First test: winning the Iowa caucuses, perceived by many as an improbable feat for a black candidate in an overwhelmingly white state. But Obama believed in the power of his ideas and ideals, and the capacity of Americans to unite around them.

Eleven months later, after more than 80 days spent campaigning in the state, Iowans awarded him victory. They had heard his soaring oratory and sensed his uncommon intelligence, but they also witnessed much more: the consistency of his calls for unifying around common purpose, rather than pandering to age-old divisions, and the way he remained unflappable and his staff disciplined no matter what tumult the campaign trail delivered.

Those qualities have become even more pronounced this fall, during an increasingly negative general-election campaign against Republican Sen. John McCain and descent of the nation’s economy into the worst financial crisis since the Great Depression. It has been Obama, not the more experienced McCain, who kept his center as events tilted crazily.

Obama has earned the Register’s endorsement for the presidency because of his steadfastness in the face of uncertainty, his clear-eyed vision for a more just America and his potential for rallying the country to do great things.

The DMR also liked Obama’s approaches to shoring up the middle class by expanding health care coverage and the creation of green collar jobs. Not mentioned in the editorial, but is well known that McCain is against subsidies for ethanol, and that view doesn’t sit well with midwesterners.

Like other newspapers, some whom endorsed Bush last time (the DMR did endorse Kerry in 2004), the DMR believes McCain has run an “erratic” campaign.

Worst of all, in grasping for political edge in his choice of a running mate, he burdened his ticket and potentially the country with an individual utterly unqualified to ascend to the presidency. Before choosing Alaska Gov. Sarah Palin, McCain emphasized the importance of experience and sound judgment in fighting terrorism and confronting a restive Russia and a rising China. He has also questioned Obama’s readiness to be commander in chief. Then he picked a running mate who clearly isn’t ready.

Sarah Palin’s unreadiness to be President is a common theme in why McCain isn’t being endorsed.

To conclude, the DMR believes, “An Obama presidency presents the best hope for a unified America that aspires to greatness again.”