As a lifetime journalist I am well aware of the differences, and suggest the philosopher is ill suited for the rigors of ideology, where suspension of belief is a necessary tool.
In politics the ideological is not an idealist, but the opposite, fear driven, averse to change, while the progressive believes he is an idealist but ends up becoming ideological when frustrated about no change.
The first real philosopher politician I met was Pierre Elliot Trudeau, former Canadian prime minister and father of today's Justin Trudeau. In his frist term he generated some 5 million pages of "White Papers", parliamentary presentations on ideas, ideals and progressive goals, including then the legalization of marijuana and free university.
Somewhere in the middle there lies a balance, but damned if I know what that is. 30 years covering governments from rural town halls to Parliament. I do know, the adage "power corrupts, absolute power corrupts absolutely" I have seen a lot of men and women startlingly changed in their philosophy after even a few months in office.