In Chile, the electoral system is so tightly bound to a particular historical era--the dictatorship--and a particular political group--the far right--that it generates tremendous conflict. It is, in fact, even dividing the right. Sebastián Piñera, currently the least popular president in Latin America, recently announced that he did not consider the binomial system a priority.
From the Santiago Times:
In a continued show of bipartisan politics, the center-right National Renewal (RN) and center-left Christian Democrats (DC) held a meeting Monday to appoint Andrés Zaldívar and Jorge Burgos to head their initiative on binomial reform.
Zaldívar, an RN senator, and Burgos, an RN deputy, will attempt to work with President Sebastián Piñera, who is an RN member himself, on the reform and hope to have a formal bill submitted to Congress by March.
Along with DC Sen. Ignacio Walker, the two parties want to take the proposal their parties had previously submitted and turn it into a concrete political blueprint for changing the binomial system.
It is only a matter of time. The far right is not happy, but consensus has slowly grown over the years. Piñera's passivity will do him no favors. It would seem to cost him very little to endorse a reform that is going to happen anyway, unless he feels he needs that nod to UDI is necessary to get other things passed.
Update: Twitter response noted that Zalvídar and Burgos aren't RN. Excellent point, which I missed. Basic idea, though, remains the same.