By last year, Congress was seeing the state-owned Chinese behemoth in a far kinder light. Sen. John F. Kerry (D-Mass.) authored a resolution applauding the company for employing thousands of Americans and helping keep the waters of Alaska clean. Rep. Stephen F. Lynch (D-Mass.) hailed the firm on the House floor, calling its chief executive “a people’s ambassador” to the United States after it rescued Boston’s port — and thousands of jobs — when a European shipping line moved out.

The congressional about-face illustrates a dramatic increase in China’s influence on Capitol Hill, where for years its lobbying muscle never matched its ballooning importance in world affairs. Members of Congress, lobbyists and other observers said China’s new prominence is largely the result of Beijing’s increasingly sophisticated efforts to influence events at the center of U.S. power — and a growing realization among U.S. lawmakers that China has become a critical economic player across America.

Although many Americans still view China with deep suspicion because of its communist system and human rights record, the results of Beijing’s image-and-influence campaign are clear. Members of Congress “are starting to understand that the Chinese are not communist but that the Chinese are Chinese,” said Rep. Earl Blumenauer (D-Ore.). China is Oregon’s biggest export market after Canada.

“China is an overarching backdrop to almost everything that I am involved with,” said the seven-term congressman, adding that on matters as diverse as the U.S. economy, climate change and energy policy, “China is something that no one can ignore.”

For years, as China steadily rose to global economic and political heights, it all but ignored the U.S. Congress, with outreach to American lawmakers left to friends in the business community. But now China has launched a multimillion-dollar lobbying effort so effective that it is challenging the heralded efforts of nemesis Taiwan.

A decade ago, U.S. politicians of all stripes routinely subjected China to attacks. Now acts of benevolence are more likely — such as a resolution commemorating the 2,560th birthday of Chinese philosopher Confucius, which the House overwhelmingly approved in October.

“There was originally this kind of anti-communist view of China,” said Sen. Dianne Feinstein (D-Calif.), who in 1979 became the first U.S. mayor to visit China when she ran San Francisco. “That’s changing. . . . China is a socialist country but one that is increasingly becoming capitalistic.”

The new openness toward China is often subtle and not shared by all. But an undeniable evolution is taking place, congressional staffers and analysts said, as members of Congress, many with increasing numbers of large and small businesses in their districts that depend on trade with China, are now far more likely to kill or water down measures opposed by Beijing.

While China maintains a huge trade surplus with the United States, U.S. exports to China have surged in recent years. In 2008, according to the U.S.-China Business Council, exports to China grew in 85 percent of congressional districts. China is now the third-biggest market for U.S. goods, after Canada and Mexico.

“People in Congress are not stupid,” said Minxin Pei, a professor of politics at Claremont McKenna College. “A few years ago, China-bashing was costless. Now they will get phone calls from worried CEOs. China is creating jobs in their congressional districts.”

Zhou Wenzhong, China’s avuncular ambassador, has visited about 100 senators and representatives in their districts during his four-year-old tenure in Washington. But he said it wasn’t simply lobbying and shoe-leather efforts that have helped China’s image in Congress.

“It’s because of our common interests that more and more members have seen the importance of this relationship,” he said. “I think their understanding of China is much deeper.”

An evolving outreach

Until the late 1990s, the Chinese Embassy employed only one diplomat focused on congressional affairs. It was a dead-end job for functionaries who rarely left the embassy, then located in a dour former hotel on Connecticut Avenue.

China counted on U.S. business groups, such as the American Chamber of Commerce, to lobby on its behalf. But with China’s accession to the World Trade Organization in 2001, those U.S. groups became reluctant to work on behalf of an increasingly potent competitor.

That spurred China to up its game on Capitol Hill, as did other events.

In the mid-1990s, Taiwan’s success in lobbying for a visa for then-President Lee Teng-hui to attend a reunion at Cornell University and give a speech infuriated China and helped precipitate a crisis in the Taiwan Strait.

Then, in 2005, the state-owned China National Offshore Oil Corp. tried to buy the U.S. oil conglomerate Unocal but ran into a lobbying operation backed by the American giant Chevron, which had the competing bid. The Chinese spent $4 million on lobbying. But it lost to Chevron as Congress passed a resolution opposing the Chinese-led takeover on security grounds.

Last year, China opened a $200 million citadel of an embassy overlooking Van Ness Street — showcasing its rising fortunes and its focus on Washington. There, the beefed-up congressional affairs office now numbers at least 10 diplomats, most of whom have studied in U.S. universities, speak perfect English and are familiar with American ways.

“The Chinese have for years been wielding a lot of influence,” said Rep. J. Randy Forbes (R-Va.), who heads the Congressional China Caucus, which has taken a tough line on Beijing. “They’ve liked to do it under the radar. But as there’s been more light shed on it, they’ve had to change their ways.”

China’s handling of troublesome U.S. politicians has evolved, too. When Sens. Charles E. Schumer (D-N.Y.) and Lindsey O. Graham (R-S.C.) proposed legislation in 2005 that would slap a 27.5 percent tariff on Chinese goods unless China revalued its currency, Beijing took a new tack. Instead of denouncing the pair on the front page of the People’s Daily, as it might have in the past, the Foreign Ministry in Beijing welcomed them on a visit to China. At the end of his trip, Schumer told reporters that he was no longer sure he would push for a vote on the bill and that he was “more optimistic that this can be worked out than we were in the past.”

From 2005 to 2009, China for the first time hosted more U.S. politicians and congressional staff members than Taiwan, according to LegiStorm.com, a congressional watchdog. China has also tripled the amount it spends on lobbying firms, including such powerhouses as Patton Boggs and Hogan & Hartson, since 2006 — although it continues to be outspent by Taiwan.

Feinstein said the views of her colleagues have become more sophisticated with time. They know that China holds a massive amount of U.S. debt and that it imports a lot of goods — $11 billion worth from her state alone last year. “I have never seen a country change as fast in 30 years as China has done,” she said.

Neutralizing Taiwan

Washington used to be home to two types of “China people,” known to insiders as the Red team, which supported China, and the Blue team, which backed Taiwan. These days China’s rising influence has succeeded in bolstering the Reds.

In 1991, Rep. Nancy Pelosi traveled to China and unfurled a banner on Tiananmen Square in remembrance of those who died during the 1989 crackdown on pro-democracy demonstrators. Last year, as speaker of the House, Pelosi returned to China, and although she continued to raise human rights issues, she focused far more on climate change and, as a congressional staffer said, “minded her P’s and Q’s.”

Some legislators who used to be considered firmly in Taiwan’s camp now lean toward China.

Del. Eni F.H. Faleomavaega, a nonvoting, 11-term member from American Samoa, is the influential chairman of the House Foreign Affairs subcommittee on Asia, the Pacific and the Global Environment and for years was considered a solid backer of Taiwan. But over the past year, the Democrat has watered down or killed pro-Taiwan legislation and resolutions.

Faleomavaega partly credited China’s improved lobbying for the shift. “Our friendliest allies — Germany, Great Britain, France and Japan — know how to work the system,” he said. “China is just trying to catch up.”

China’s strongest backers in Congress are also becoming more vocal, especially the 60-member U.S.-China Working Group, led by Reps. Rick Larsen (D-Wa.) and Mark Steven Kirk (R-Ill.), who represent districts that do considerable trade with China.

“We bought China when it was low,” Larsen quipped. “There was nowhere for it to go but up.”

Staff writer Steven Mufson contributed to this report.