As far as I can tell we're not facing this problem alone, but we're pretty young as a democratic society and most of our politicians inherited their position or remained on it under an amnesty after Franco's dictatorship (hence the usage of "caste").
I think (though it's hard to analyze when you're involved in the situation) we're in the middle of a social and generational change. We've got daily news of corruption cases amongst the mainstream parties and people are really fed up. "Podemos" (literally "We can", a left-wing grassroots party) rose as an alternative to that political caste, and most surveys situate them as a heavy contender (if not winner) for the upcoming elections.
Not long ago you'd hear lots of people claim they were not interested in politics, so they were pretty much puppets in the hands of our politician's interests. Nowadays, thanks to the 15M movement and Podemos, there are political debates on Saturday night prime time. Politics are in vogue.
Perhaps that's the government competition you were talking about?
We'll see what happens.