We can usefully classify politicians into three categories: caretakers, practical visionaries and values-transformers.

Caretakers maintain the status quo, a task that boils down to throwing a fiscal bone to every politically powerful constituency and doing so in a manner that does not create career-threatening blowback.

Caretaker politicians may or may not have what President George H.W. Bush famously called "the vision thing," but their actions are all of the caretaker variety, regardless of their soaring rhetoric.

Caretaker politicians take credit for things that would have happened even if they'd lost the election and some other caretaker politician had held the office: the new school would have built anyway, the strike settled one way or another, and the nation would have exited from the unpopular discretionary war.

The signature accomplishments of caretaker politicians always leave the status quo power structure and constituencies firmly in place; ObamaCare is an excellent example.

Practical visionaries use their political capital to push through long-term, unsexy infrastructure projects that do not necessarily have powerful constituencies pushing for them and may have politically potent enemies. Examples include rebuilding or extending sewer systems, systemwide renovation of water works or power transmission lines, etc.

These long-term projects require major commitments of funds and competent long-term management, both of which must be cultivated by the practical visionary politician. They may also require overcoming significant political resistance from constituencies who are not benefiting (at least in their view) from the immense investment of public treasure.

Where the caretaker is happy to glad-hand his/her way through the short-term fray of competing demands, putting our fires and resolving minor battles, the practical visionary must have the vision and fortitude to keep investing effort and political capital in long-term projects that may not be sexy or popular.

The signature accomplishments of practical visionaries tend to be large-scale projects that were not slam-dunks: caretakers do not risk their political capital on long-term, unsexy projects, nor do they have the persistence, vision and character needed to work diligently for years to persuade or cajole doubters and then ensure the project is competently managed to completion.

Practical visionaries have "the vision thing" for concrete projects: revamp teacher education from the ground up, a new water treatment plant, an interstate highway system, etc. Their values are oriented toward improving the basics of civilization: water, waste, transport, education, etc. in fundamental, long-term ways.

Practical visionaries are often under-appreciated in their own time; they may only be appreciated long after they have retired or passed on.

Practical visionaries are also capable of wreaking great damage because they grind through even formidable opposition: those pushing "urban renewal" projects that bulldozed "slums" (i.e. affordable housing for marginalized populations) so freeways could tear the heart out of neighborhoods were convinced that making it easier for suburbanites to drive to their jobs in the city was worth far more than intact neighborhoods. Their confidence in that suburban mindset laid waste to many U.S. urban centers.

The third category of politician is very rare: those who can change the values of the populace and thereby transform the political landscape.

This type of politician is adept at transforming what appears to be unresolvable conflicts by establishing a values-based common ground that enables warring constituencies to bypass the old battle lines. This rare breed is not ideological, as ideologies are what create and solidify the conflicts and battle lines.

Values-transformers find a way to make every constituency feel as if they have participated in the solution, or even better, that the solution arose from their core values. Those constituencies that lose power as a result are treated with respect rather than denigration.

Solving profoundly structural problems by establishing a new foundation of values that most can embrace positively is the hallmark of leadership.

Either those with these leadership skills are avoiding politics or the voters are rejecting them in favor of caretakers who are incapable of challenging political powerful constituencies or finding common ground for desperately needed systemic reforms.