Die spielen schon seit Jahrzehnten das gleiche Spiel. Alle paar Wahlperioden Erstwähler mit einer gezielten Werbekampagne verarschen, ihr Kreuz bei der FDP zu machen, dann maximal korrupte Klientelpolitik, draufhin eine Zeit lang den Ball flach halten und das Gleiche von vorne.

Die FDP ist so korrupt, dass sie nicht im Geringsten auf die staatliche Parteienfinanzierung angewiesen ist, um groß angelegte Werbekampagnen zu fahren und ihr Spitzenpersonal fürstlich zu bezahlen. Die können das Spiel sehr lange spielen, solange die Ergebnisse für die Geldgeber stimmen.

Germany - Deutschland but in English ;)

The question was how the FDP could keep its place in the German political spectrum for decades.

The answer is really simple. They have been doing this for decades. Fool naive first-time voters with a targeted campaign to vote for FDP, then do maximally corrupt clientele politics, afterwards lay low for a bit, and then rinse and repeat.

The FDP is so incredibly corrupt it doesn't need (vote count based) state financing for political parties in order to pay for large scale advertising campaigns, and to pay their leadership obscene salaries. They can play this game very long, as long as the results for their financial backers are right.

They always saw themselves ad the kingmaker and presented themselves as a liberal alternative to the other parties. Although effectively they forgot about everything liberal besides their economic policies as soon as they got into power.

Effectively they and the CDU/CSU were symbiotes of one another. The CDU always could pretend to be more conservative on economic things and then drop this for their FDP partners, while the FDP by sheer necessity had to drop all their topics besides market-liberalism.

This worked, and I think people knew that if you voted FDP you would get CDU politics anyway, but you could say you didn't vote for them.

And I mean, the last time FDP went into a coalition with someone besides the CDU/CSU they basically acted as fifth columnists.