BEAVERTON, Ore. — President Obama on Friday lashed out at critics within his own party as he accused fellow Democrats of deliberately distorting the potential impact of the sweeping new trade agreement he is negotiating with Asia and standing in the way of a modern competitive economy.

With the cutting tone he usually reserves for his Republican adversaries, Mr. Obama said liberals who are fighting the new trade accord, the Trans-Pacific Partnership, were “just wrong” and, in terms of some of their claims, “making this stuff up.” If they oppose the deal, he said, they “must be satisfied with the status quo” and want to “pull up the drawbridge and build a moat around ourselves.”

“There have been a bunch of critics about trade deals generally and the Trans-Pacific Partnership,” he told an estimated 2,100 workers at the Nike headquarters here. “And what’s interesting is typically they’re my friends coming from my party. And they’re my fellow travelers on minimum wage and on job training and on clean energy and on every progressive issue, they’re right there with me. And then on this, they’re like whupping on me.”

But Mr. Obama said that he had no political motive for supporting freer trade with Asia. “I’ve run my last election,” he said. “And the only reason I do something is because I think it’s good for American workers and the American people and the American economy.” And so, “on this issue, on trade, I actually think some of my dearest friends are wrong. They’re just wrong.”