Members of the Social Democratic Party (SPD) cannot have too many qualms with their party head and Germany's vice chancellor: Sigmar Gabriel is as visible as ever. He gives various interviews and highlights the SPD's successes within the governing grand coalition - such as the introduction of a national minimum wage and a quota for female board members. Gabriel has traveled to Saudi Arabia and advocated respect for human rights there. Recently the SPD's headquarters issued press release number 65 for this year: Gabriel is visiting a vocational training program for single parents in Berlin. No one could say he's neglecting the pillars of his party's platform.

Merkel remains popular

But is all of that going to make a difference? The latest polls show the SPD's support stuck at around 24 percent. It feels like it's been that way for years. Angela Merkel's Christian Democratic Union (CDU) is well in front of that score at 41 percent - taken together the CSU, its Bavarian sister party.

Germans like their chancellor, and she's at the top of the list of the best-liked politicians. All in all, things are going wonderfully in the country. Germany can keep chugging along. There's no end in sight to the Merkel era.

When it comes to who should run in the next federal election in 2017, the latest polls present a depressing landscape for the SPD. Among those surveyed, 61 percent want Merkel to remain in office. But who has the best chances among those in the SPD? First place went to Frank-Walter Steinmeier, the current foreign minister who already suffered a bruising defeat against Merkel in 2009. Now 36 percent of respondents say they believe in him, while 25 percent think Gabriel - the party's head - could become chancellor. That's a sobering result for the SPD with its grand tradition.

That's why Gabriel didn't seem exactly relaxed when the press recently wanted to know whether the SPD will even be presenting its own candidate in 2017. Would it not be better - a journalist slyly asked - for the SPD to campaign from the outset as the CDU's junior coalition partner? Gabriel's facial expression betrayed that he'd seldom heard something so laughable.

A challenger is needed

Sigmar Gabriel actually has to run. In 2013, he was already head of the party when he let Peer Steinbrück have a go instead. Steinbrück suffered a heavy loss against Merkel, just like his predecessor Steinmeier. Steinbrück recently described his attempt as a mistake.

If Gabriel doesn't stick his neck out now, he won't be able to hold on as head of the SPD for long, say insiders in Berlin. But that's also likely to be true if he delivers another bitter loss.

Perhaps the president of the European Parliament, Martin Schulz, will try to win voters' favor. A serious proposal? The "Bild" tabloid published a rumor to that effect several days ago. Schulz delivered a good campaign last year to become head of the European Commission, but he narrowly lost to the current conservative officeholder, Jean-Claude Juncker.

For many Social Democrats, though, the idea of a narrow loss almost offers a glimmer of hope.

New rumors again and again

Sources in Berlin say these rumors prompted weary smiles at the SPD headquarters. There are also some claims floating around that Family Affairs Minister Manuela Schwesig could be built up as the future party head - equally a source of weary smiling at the SPD. The names Hannelore Kraft (minister-president in the state of North Rhine-Westphalia, who has said she does not want to run as chancellor) and Olaf Scholz (mayor of Hamburg, who says he's satisfied with his current position) have also long been in the rumor mill, but that doesn't make the candidacy of either any more likely.

The SPD's biggest hope is that the chancellor runs out of steam and doesn't want to continue in 2017. That would probably mean Defense Minister Ursula von der Leyen would step in for the CDU, which would give the SPD significantly better chances. That doesn't seem likely, however. The SPD is probably in for some more disappointments ahead.

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