President Obama will make his encore on the German stage with a speech at Berlin's landmark Brandenburg Gate on Wednesday, returning as a mere mortal rather than the rock star who captivated a country looking for a transcendent U.S. political figure five years ago.

In 2008, then-candidate Obama spoke before 200,000 people in Berlin, assuring legions of adoring fans he would usher in a new era of American diplomacy. Now the president, bruised from a series of battles in Washington, will address a few thousand invited guests.

For a growing number of Germans, Obama failed them where it mattered most: the protection of civil liberties. European critics point to the president's inability to close Guantanamo Bay, an unprecedented drone campaign overseas and most recently, revelations about top-secret phone and Internet surveillance programs as proof that Obama neglected the very ideals intertwined with his political identity.

"That star power is gone now," Christian Schmidt, an Internet technology specialist from Berlin, told the Washington Examiner in a telephone interview. "Most people still like him -- it's not like he's [George W.] Bush -- but he hasn't lived up to expectations. The last few years have been a reality check."

Particularly problematic for Obama is the National Security Agency's widespread collection of phone records and Internet data, a subject German Chancellor Angela Merkel pledged to press Obama on during his visit.

Ahead of the president's speech, some German politicians compared the Obama administration with the East German Stasi police, which infamously spied on and intimidated its own citizens. On the streets of Berlin, some carried signs that said, "Yes we scan" and others mockingly likened Obama to Martin Luther King Jr., chanting, "I have a drone."

"The Germans are particularly sensitive to [the NSA programs]," explained Alexander Privitera, director of the Business and Economics Program at the American Institute for Contemporary German Studies. "He has to convince them that the goal is not to spy on Germans and Europeans."

Assessing how Germans now view Obama, Privitera added, "He is, after all, a man like everybody else; he cannot walk on water."

But in giving a speech commemorating President John F. Kennedy's "ich bin ein Berliner" Cold War remarks, and from the same site as President Ronald Reagan's "tear down this wall" address, Obama could have difficulty managing expectations.

"The overarching point that he's going to make is the exact same level of citizen and national activism that was characterized in the Kennedy speech and in the Cold War needs to be applied to the challenges we face now, even as they are more distant from our own lives," Deputy National Security Adviser Ben Rhodes said.

Still, the president would gladly trade his approval ratings at home with those he receives in Germany -- and Merkel welcomed Obama's visit so close to her own re-election bid.

A Pew Research Center poll released Tuesday, for example, found that 88 percent of Germans have confidence in Obama "to do the right thing in world affairs." But even those findings were offered with a major caveat.

"Even though Obama remains popular, he has disappointed the German public on certain issues," Richard Wike, associate director of the Pew Research Center's Global Attitudes Project, said, pointing to a growing number of Germans who say Obama "has not been as multilateralist" as they wanted nor "done enough on climate change."