COLOGNE, Germany — It is campaign season here along the Rhine River, and the main street in the gentrifying neighborhood of Deutz could be viewed as something of a microcosm of German politics.

Chancellor Angela Merkel’s Christian Democrats had half a dozen campaigners under their orange and white umbrella, the largest group on the block. The Greens were set up in front of the organic food store, just a few feet from their would-be coalition partners in the state Parliament, the Social Democrats.

Across the street, Ms. Merkel’s coalition partners, the Free Democrats, seemed to be in the most difficult position of all, near a pair of voluble drunks with one empty and three full bottles of cheap rosé in front of them. The party leadership in Berlin only wishes its problems were so easily left behind.

The pro-business Free Democrats, also known as the F.D.P., have failed to reach even the 5 percent threshold for representation in five of the last six state elections, including a dismal showing of just 1.2 percent in Saarland in March. Their approval ratings plunged so quickly and the state defeats were so stinging that analysts have called the party’s very existence into question.