BERLIN (Reuters) - With the novelty value of their new leader fading, Germany's Social Democrats need to retain power in regional elections on Sunday and a week later if they are to pose a serious threat to Chancellor Angela Merkel in September's national vote.
Sunday's vote in the far northern state of Schleswig-Holstein, and an election in the large western region of North Rhine-Westphalia (NRW) on May 14, are opportunities the Social Democrats (SPD) must seize to regain momentum.
The left-leaning SPD enjoyed a revival in the polls early this year after nominating former European Parliament president Martin Schulz as its candidate to run against Merkel.
But the "Schulz effect" failed to translate into votes for the SPD in an election in the state of Saarland in March. In Schleswig-Holstein and NRW, the party can ill-afford to lose to Merkel's conservative Christian Democrats (CDU) again.
"If these two state elections are a flop for the SPD, all is not lost, but it will be hard to win the election in September," said Gero Neugebauer, a political scientist at the Free University in Berlin and an SPD expert.
"Merkel is commanding the stage, presenting herself to German voters as a crisis manager," added Neugebauer, pointing to her meeting this week with Russian President Vladimir Putin on the conflicts in Syria, Ukraine and other issues.
"With Schulz, people are asking 'where's the beef?' He talks about social justice but people want to know what that means."
With a focus on fighting inequality, Schulz is trying to sharpen the SPD's policy edge, blunted by spending seven of the last 11 years sharing power as junior coalition partners with Merkel's CDU at the national level.
That arrangement turned voters off the two big parties and fed the rise of the anti-immigration Alternative for Germany (AfD) last year, though it is now losing support after a bout of infighting and risks a regional washout in Schleswig-Holstein.
Merkel's Christian Democrats have profited from the AfD's demise at the national level. Two polls on Thursday showed her conservative bloc extending its lead over the SPD to six and seven percentage points respectively.
Schleswig-Holstein is a richly agricultural and mainly rural region of 2.3 million voters that juts north of Hamburg and borders on Denmark, and it is a leader in Germany’s renewable energy industry.
Jobs and wind farm plans are among the regional issues in the election in Schleswig-Holstein, where the SPD will be defending an incumbent state premier - Torsten Albig - for the first time since Schulz's nomination as party leader in January.
Albig hopes to benefit from his incumbency advantage to return to power with his coalition of the SPD, the Greens and the South Schleswig Party (SSW), which represents the ethnic Danish minority.
However, a survey by pollster Forschungsgruppe Wahlen for national broadcaster ZDF published on Thursday put support for the CDU at 32 percent in Schleswig-Holstein, ahead of the SPD on 29 percent. That would leave a "grand coalition" as the sole governing option for the rivals - a scenario that could also arise again at the federal level after the September election.
Editing by Mark Heinrich