[d_silin]

Centrist positions are inherently unstable (think top of the hill) because they require active efforts to maintain the balance between factions prone to polarizations (left->far-left, right->far-right). It requires consistently good statesmanship or strong external challenge for opposing factions to act in united manner.

[Terr_]

While setting proactive centrist initiatives might be hard, centrist sentiment with passive inaction is very very easy. All you need to do is tut-tut occasional "excesses."

In other words, the centrism of taking risks is very different from the centrism of avoiding them.

[dyauspitr]

It depends on how the populace feels. It could also technically be a valley with the extremes on either side. Honestly though I think the centrists can never find positions people can get rabid about because by definition it calls for moderation.