Such developments have led to the phenomenon of ' creeping presidentialism' , in that prime ministers, under media and other pressures, have increasingly distanced themselves from their parties, cabinets and governments by cultivating a personal appeal based upon their ability to articulate their own political and ideological vision. Nevertheless, although prime ministers who command cohesive parliamentary majorities and are supported by unified cabinets wield greater power than many a president, their power is always fragile because it can be exercised only in favourable political circumstances. Ultimately, prime ministers are vehicles through which parties win and retain power; prime ministers who fail in these tasks, or become unmindful of the role, rarely survive long.