Ronald Reagan demonstrated immediately that he lived in a childish world ("Voodoo economics" anyone? It makes my Laffer curve just to think about it!). Yet the people flocked to the "affable idiot" in droves, especially blue-collar workers who soon after PATCO ceased bragging that they had voted for him. Despite his schoolyard approach to diplomacy, the American voters loved his Bedtime for Bonzo Goes to Washington act enough to call for an encore. Later, George HW Bush -realizing that he couldn't live up to his "Read My Lips" boast- did the adult thing and pushed for higher taxes and cost himself an extended stay in DC.
Bill Clinton, whose juvenile side remains evident to this day, managed to survive Republican attempts to squash his programs and to remove him from office over a "sowing of the oats" that should have ended long before. His VP, Al Gore, resumed the Carter Energy Doctrine while adding into the presentation adult-level education streams to support the goal. Trying to do the adult thing regarding American energy usage cost Gore the White House. I can't say that his personal energy excesses helped his cause much. But taken together, Gore's personal and professional energy aspects made it much easier for Pitt's "small fraction of a man" to take the Oval Office - with a lot of help from the Brooks Brothers rioters and by imperious SCOTUS edict.
Dubya Bush was the alcoholic America wanted to have a beer with, remember? It took an serious economic crisis to lower his approval levels to the point that even a half-white guy (per Wanda Sykes) was an acceptable alternative. That just shows how desperate America became, taking the radical step of allowing a non-white to take power over WASPland. One can argue whether or not Obama's poor performance can be labeled as an adult approach to the various problems that Washington represents (I for one do not), but he isn't appealing to that ignorant low-brow segment of our population that aided Nixon, Reagan, Clinton, and Dubya. These folks are glued to Sarah Palin.