BERLIN — German Chancellor Angela Merkel begins an official visit to Washington on Tuesday and will be honored with a 19-gun salute, a lavish White House dinner and the U.S.' highest civilian award.
But at home, the "world's most powerful woman," as she is often labeled, has suffered declining popularity after a series of political missteps in the past six months, and she is visiting while Germany is at the center of a health crisis brought on by an outbreak of the deadly E. coli bacteria.
Some observers wonder whether Mrs. Merkel, in her second term as chancellor, can survive politically. The question is raised frequently because of recent election losses suffered by her Conservative Democratic Union (CDU) and her sudden opposition to nuclear energy.
"She reversed herself in a huge way," one lawmaker said privately. "And by doing this, she hurt her credibility."
One party leader from the western state of Hesse broke ranks publicly with Mrs. Merkel in a written manifesto that appeared in the press on Monday as she was flying to Washington.
Conservatives "are losing what is most important to their core voters, namely their loyalty to basic principles," Christean Wagner said in an 11-page criticism of his party.
But he added that Mrs. Merkel remains unbeatable, at least for now. Others agree.
"There is no Brutus to cut her down on the steps, to speak metaphorically. She cut the heads off of any competition she had," said Michael Sturmer, a political commentator who worked as an adviser to CDU Chancellor Helmut Kohl in the 1980s.
Gerd Langguth, a political science professor at the University of Bonn who wrote a 2010 biography of the chancellor, noted Mrs. Merkels talent for power politics.
"Over the years, she has managed to push aside any competitors in her party very skillfully," he said.
Still, a number of seemingly clumsy and waffling political decisions have hurt her and the CDU. A May 31 poll by the Forsa research institute showed their support dropping for the third time this year, to 30 percent. The Greens, once only a fringe party, are trailing by just 4 percentage points in second place.
Last year, Mrs. Merkel promised to keep Germany's nuclear power stations operating through the year 2035. Nuclear plants provide about 23 percent of Germany's energy.
After her party suffered a devastating election loss in Baden-Wurttemberg after 58 years in control of the state legislature, Mrs. Merkel abruptly changed her position. She promised to shut down the country's 17 nuclear plants within 11 years.
She infuriated Britain and France when she sided with Russia and China by abstaining on the U.N. Security Council resolution on Libya to protect civilians in the civil war against Col. Moammar Gadhafi.
Some say that is why President Obama skipped Germany last month on his European trip, which included Britain and Poland. The high-profile Washington visit is seen as an opportunity for both leaders to establish warmer relations.
Mr. Obama will present her with the Presidential Medal of Freedom, the highest civilian award bestowed by an American leader. In a German newspaper interview published Monday, Mr. Obama praised Mrs. Merkel.
"I consult with the chancellor on every important issue on my international agenda, and I very much appreciate her pragmatism and straight talk," he said.
• Sumi Somaskanda in Berlin contributed to this article, which is based in part on wire service reports.