The troublesome challenger

Only the timing was a surprise. The Social Democratic Party's parliamentary leader Frank-Walter Steinmeier didn't want the job, while party chairman Sigmar Gabriel couldn't do it. That left the field open for the man who is currently only an ordinary member of parliament - Peer Steinbrück - a rhetorical maestro, an attacker, an expert in financial and economic politics. In other words, he's a man for a crisis.

That makes him Chancellor Angela Merkel's most dangerous opponent. It will be a long campaign, with the election not scheduled until next September, but it promises not to be boring.

Not always the diplomat

Steinbrück has developed his reputation from "Peer who?" to "Peer knows more!" The northern German with a sharp tongue is an atypical politician. He is an administrator with a string of leading positions behind him.

His domineering tone has often caused consternation in the democratically minded Social Democratic Party (SPD). His internal party critics fear a return of Gerhard Schröder's authoritarian political style. He does not cozy up to the grass roots nor does he seeks the comfort of his party's center ground at any cost.

Steinbrück speaks openly, sometimes provocatively and rarely diplomatically. He once described the left-leaning members of his own party as cry-babies. He speaks his mind more often than other politicians. For many in the SPD, soon reaching its 150th birthday, Steinbrück is too aloof, too gentrified, too intellectual. But he is respected, though not particularly by leftists, who consider him too market-oriented.

Effectively, Steinbrück has two election campaigns to fight. First with members of his own party, who have yet to be convinced by their own candidate. The party conference vote is still to come, and the percentage he wins there will give a good indication of how seriously his party colleagues mean to push Steinbrück as the challenger to Merkel.

Another peculiarity of Steinbrück's candidacy is the fact that he must now fight the campaign as part of a troika with Gabriel and Steinmeier. The loner will have to prove his skills as part of a team. As an instinctive attacker, he will have to find the balance between the leftists and the social welfare reformers in his party if he wants to get the party members and the SPD's core voters behind him.

Different style

There are only minor differences between Merkel and Steinbrück on the euro crisis, which will be the central issue of this campaign. Both are considered capable crisis managers, and Steinbrück could even reap a few conservative votes on the issue. The question will be how this issue will be presented on the campaign trail.

Despite his glittering resume as an administrator, Steinbrück has little campaign experience. When shaking hands in town squares, he often comes across as cold, distanced and even arrogant. But his moment comes as soon as he's in front of a microphone. He can polarize opinion, but he can also entertain, even make his audience laugh - not exactly the current chancellor's strength.

Their styles will then probably be what separates them on election day. Merkel's reserved, stateswoman-like demeanor still comes across well with the center of German society. But Steinbrück can score points in the Merkel heartlands because of his economic expertise, especially since the political differences between the two are marginal.

But if Steinbrück is to seriously threaten the chancellor at the polling booth, then questions of coalitions will arise. The SPD has already declared that that it wants a coalition with the Greens, a party that Steinbrück constantly quarreled with when he was state premier of North Rhine-Westphalia.

The biggest unknown is the economy. If it weakens next year as expected, then that could play into Steinbrück's hands, especially since the government coalition has now been arguing with itself more than with the opposition for some time now. Either way, it will be a long and intriguing battle between personalities and styles. Not that it is likely to lead to a significant change in Germany's political direction. The platforms are similar - the adversaries very different.