What is it about conservatives that so many Republican presidents don't understand? Why don't they get that cultivating conservative support, and selling conservative ideas to the general public is the only way they can weather the political storm and actually govern? And why do all of them, other than Ronald Reagan, keep making the same "betray the base" mistake?

President Donald Trump is making that mistake right now as he declares war on the handful of House Republicans who doomed the GOP Obamacare replacement bill. Last night he singled out three of those Representatives in particular:

But that's nothing compared to what White House Press Secretary Sean Spicer did earlier on Thursday when he hinted the president may campaign against Freedom Caucus members in the 2018 primary elections.

If President Trump continues on this path, he'll have a new enemy to contend with called "history." Because history shows that when Republican presidents turn on conservatives and conservative ideals, they end up failing badly.

The reason is simple: the Republican base is still overwhelmingly conservative. A Republican president can certainly earn some political capital by seeking more moderate supporters when good opportunities arise, like with the nomination of the highly respected and liked Judge Neil Gorsuch to the Supreme Court. But when they support more liberal causes or policies, they usually sacrifice their base of support and almost never get a shred of backing from those moderates in return. Worse yet, these moves almost always leave the country in worse overall shape.

The best examples of this kind of failure were produced by President Richard Nixon, who expanded the Democratic Party's "Great Society" welfare programs, boosted the size of government with new agencies like the EPA, and—worst of all—raised taxes. But none of those fence-mending/coalition-building initiatives worked to gain Nixon any real bipartisan support in Washington, evidenced most clearly by the spirited efforts to impeach and eventually force his resignation during the long Watergate scandal. And by the time he did step down, Nixon's economic policies had worsened the stifling economic woes of the 1970s.

Less extreme, but still serious, is the case of President George H.W. Bush. Bush broke his promise to never raise taxes and backed a Democrat tax hike that plunged the nation into the recession of 1991 and helped push him out of office a year later. Gerald Ford suffered the same re-election failure after pursuing dovish policies with the Soviet Union and waffling on tax policy. Even the enormously popular Dwight Eisenhower helped doom his own party to midterm election failures in the 1950s and general election failure in 1960 after his high tax policies produced multiple recessions.