According to Robinson, the indignados have their roots partly in protests earlier this year against an anti-piracy law governing Internet downloads. Since then, protests have grown in scope and seriousness. Robinson notes a protest sign that reads: DEMOCRACY IS A 2-PARTY DICTATORSHIP. The object of complaint is "a two-party system dominated by José Luis Rodríguez Zapatero’s beleaguered ruling socialists and the conservative People’s Party (PP) opposition," described by a protester as "alternation without alternatives." It's the Socialists who've enacted austerity measures, and for that, Robinson reports, they suffered major losses in parliamentary elections. The problem, from the indignado perspective, is that voters didn't abandon Zapatero's party for the new, independent Left Unity party, but turned in typical populist fashion to "racist" anti-immigrant candidates. Left Unity and the indignados appear to believe that Spanish election laws handicap independent parties. Among their demands, according to Robinson, is election-law reform.
The perception that Bipolarchy prevails is reflected in a Wikipedia article on Spanish political parties. "Spain has a multi-party system, which means that there are two dominant political parties," it reads. with extreme difficulty for anybody to achieve electoral success under the banner of any other party." The same article showed that ten different parties were represented in the Spanish legislature after the 2008 elections, but most of the smaller parties were ethnic-nationalist (Basque, Catalonian, etc.) in orientation, with inevitably limited support nationwide. Spanish election law constrains the nationalist parties somewhat since people associated with terrorist organizations, or associations linked to terrorism, face severe legal obstacles to electoral participation. According to this article by Manuel Alvarez-Rivera on Spanish election law, the country employs a form of proportional representation, but to prevent "fragmentation" imposes a threshold for eligibility in the allocation process. A party must get 3% of all valid votes cast (counting blank ballots) in any given constituency to be eligible for any seats. Alvarez-Rivera notes that the law especially handicaps smaller parties aiming for nationwide rather than regional or ethnic support.
Although in most cases the three percent barrier is of little importance, the cumulative effect of the application of the d'Hondt rule over a large number of mostly small-sized constituencies - the provinces - makes a significant difference, given that the largest average method has a tendency to favor the major parties, which intensifies as the constituency size decreases: notice how the effective representation threshold, as a percentage of the total vote, increases as the number of seats to be allocated decreases. As a result, minor parties with evenly spread support usually have very little chance of winning seats outside the larger constituencies.
In addition, election law seems to favor the already successful. Advertising time in the media appears to be allocated based on performance in the previous election, which would automatically handicap new parties while reinforcing the "minor" standing of parties that could well do better next time, depending on other circumstances.
If Bipolarchy conditions do exist in Spain, they remain more fluid than in the U.S. While the Socialist Party has been a constant since the death of Francisco Franco and the re-establishment of parliamentary democracy, the opposition has been concentrated first in a "moderate" Union of the Democratic Center, then in a center-right Popular (aka People's) Party. Socialist dominance has tended to marginalize parties to its left, from the Communists to the more recent United Left. Arguably, the marginalization of the radical left, more than an equivalent marginalization of the radical right, is a defining feature of Bipolarchy, despite a predictable American assumption that a "Socialist" party must be radical-left by definition. In the U.S., it serves the purpose of both major parties to identify the Democratic party with the left. Republicans identify Democrats with the left in order to ascribe to it all the sins of the entire global left, while Democrats hope to convince anyone to the left of Republicans that the Democratic party is their only real hope for change. I don't know enough about Spanish political rhetoric to know whether similar processes prevail there, but if they did it wouldn't surprise me. I don't mean to suggest that Bipolarchy is a conspiracy against the "real left," if there is such a thing, but it does seem to work out that way in practice. In any event, it's the "real left" that demands change in Spain.
Alvarez-Rivera concludes: "In the course of the last quarter-century, rectified PR has contained parliamentary fragmentation in Spain. Although the system does not always guarantee political groups legislative representation in proportion to their electoral strength, it has facilitated the formation of stable governments, and in this manner it has helped to consolidate Spain's once-fragile democratic institutions." The question Spain seems to face now is whether consolidation and stability are achieved at the expense of responsiveness to new mass movements. Left-leaning media may overstate the importance of mass demonstrations or the gravity of their complaints, but the question still arises, and not only in Spain, whether party-based politics turns a kind of democracy into a kind of dictatorship everywhere it emerges.