Laura Meckler reports on the presidential race.O

Sen. Joe Lieberman speaks as Israel’s Defense Minister Ehud Barak, left, and Sen. John McCain, center, listen during a press conference in Sderot, southern Israel, Wednesday. Photo: Associated Press

For the second day in a row, Sen. John McCain’s campaign linked al Qaeda in Iraq to Iran — an assertion Democrats say is misleading if not outright inaccurate. The McCain campaign, which acknowledged that the senator misspoke on Tuesday, insisted that its statement today is fully supported by facts.

The dispute came on the fifth anniversary of the U.S. invasion of Iraq and is likely to persist throughout this election year, as McCain makes the case that U.S. troops need to stay in Iraq. Democratic candidates Sens. Hillary Clinton and Barack Obama both promise to begin withdrawing forces if elected.

At issue is whether forces in Iran, an overwhelmingly Shiite nation, are supporting al Qaeda, a Sunni terrorist group. U.S. intelligence agencies believe that Iran’s security forces have been training and supplying weapons to Shiite militants in Iraq (a charge Iran denies).

Less clear is Iranian influence on al Qaeda, but McCain’s statement today asserted a link: “Al Qaeda and Shia extremists — with support from external powers such as Iran — are on the run but not defeated.”

A McCain adviser said that the statement was carefully written to avoid implying with certainty that it was the Iranian government that is supporting al Qaeda. Rather, he said, there is “ample evidence” that other forces in Iran were doing so. The aide suggested, however, that it was hard to believe that elements of Iran’s power structure couldn’t be at least complicit in these efforts.

To support the claim, the campaign provided articles from conservative publications such as the Weekly Standard.

The campaign does concede that McCain was wrong yesterday when he said that Iranian operatives were “taking al Qaeda into Iran, training them and sending them back.” In fact, American officials believe that was the case with Shiite militants operating in Iraq. McCain quickly corrected himself, after a prompting from his friend and colleague, Sen. Joseph Lieberman, a Connecticut independent. He made similar comments earlier on a radio program, though he did not correct those.

Democrats saw no distinction between the two statements and pounced — again. “Either John McCain is purposely playing politics with the facts on the ground or he doesn’t understand the threat facing Iraq and our brave troops,” said a statement today from DNC Communications Director Karen Finney.

And a coalition of left-leaning groups hosted a conference call to argue that McCain’s description of Iranian influence in Iraq is misleading regardless of whether there is some evidence of Iranian influence on the margin.

“The facts on this are in a very grey area that intelligence agencies debate and go back and forth,” said Brian Katulis of the Center for American Action Fund. “It seems highly improbable that there’s broad Iranian support for al Qaeda figures.” For McCain to state “in a blunt way” that there is such a connection, he said, “is utterly misleading.”

He added that it was similar cherry-picking of intelligence that led the U.S. into the Iraq war in the first place — five years ago today.

UPDATE: Late this afternoon, Obama’s campaign joined the criticism. “We wish the McCain campaign well as they try to figure out the difference between Iran and al Qaeda,” spokesman Bill Burton said in a statement. He went on to attack McCain for supporting the Iraq war in the first place.