Rainier Ehrhardt/AP Photo

BELLEVUE, Wash. - Trade was the word at Mitt Romney's events in a suburb outside Seattle, where he continued to assail China for being a "currency manipulator" that the president has allowed to "walk all over" him.

"When this president ran for office, he said he was concerned about how China was not playing fair, not playing by the rules, and he said he'd take them to the mat," said Romney, speaking to a crowd of hundreds at the Highland Community Center in a suburb just outside Bellevue. "Well, since then, they've walked all over him. What China does is cheat when it comes to trade policy."

"And you can't blame them for trying; you have to blame us for letting it go on," he said.

Romney saw another morning of huge crowds, speaking to the main room of supporters before working an overflow room where another couple of hundred people had gathered.

Romney, who has spoken extensively about how he'd deal with China differently from how Obama has if he's elected, focused largely on preserving American innovation, ignoring the other GOP candidates.

"And then, wait, Boeing, get ready, all right - China wants to start making big aircraft," said Romney. "Guess whose designs and technologies they're going to try to steal? They hacked into the computers in corporate America and the computers in our governmental sites."

"In addition to all those other things, they also artificially hold down the value of their currency. Why? So their prices are artificially low, so they can take jobs and get business," he said. "By the way, what does a country do after they've wiped out their competitors? Why then of course, they rise it right back up."

Washington State voters will caucus Saturday.