ideologue - one who zealously advocates an ideology.
ideology - the body of doctrine or belief that guides an individual.
In discussing the Republican position in negotiations about the federal debt ceiling and spending, Barack Obama said this: "
One of the major obstacles in negotiations is the Democrat insistence that taxes have to be raised. The euphemism of choice is "increased revenues," but revenues come from taxpayers, so ....
The Democrat position is political and ideological, not practical. They use taxation as a way to create, exacerbate and exploit class envy, and to show constituents how they are punishing the enemy; i.e., selected segments such as the "rich" and "big business." Obama and the Democrats are so insistent on this ideology, that they will do it even if it means decreasing the amount of revenues the government receives:
So when Obama talks about those who are "locked into ideologically rigid positions," he's really talking about himself. (Again.) And follow his advice -- remember at the polls.