WHAT IF THE WORST HAPPENS?

Michael Gerson in the Washington Post:

Every Republican of the type concerned with winning in November has been asking the question (at least internally): “What if the worst happens?”

The worst does not mean the nomination of Ted Cruz, in spite of justified fears of political disaster. Cruz is an ideologue with a message perfectly tuned for a relatively small minority of the electorate. 
....

No, the worst outcome for the party would be the nomination of Donald Trump. It is impossible to predict where the political contest between Trump and Hillary Clinton would end up. Clinton has manifestly poor political skills, and Trump possesses a serious talent for the low blow. But Trump’s nomination would not be the temporary victory of one of the GOP’s ideological factions. It would involve the replacement of the humane ideal at the center of the party and its history. If Trump were the nominee, the GOP would cease to be. 

Michael, Michael, the "humane ideal at the center" of the Republican Party disappeared years ago, and the racist, sexist, loathsome Donald Trump candidacy of today is the creation of the GOP, your very own Frankenstein's monster, who is now out of control.  Trump says in plain language what the other so-called establishment Republican candidates speak in veiled code language.  (Wink, wink, nudge, nudge, you know what I mean.)

As for Hilary Clinton's "manifestly poor political skills", I wonder if you watched any part of the eleven hour Benghazi!!! hearings, in which Clinton made Trey Gowdy and the other Republicans on the committee look like bumbling fools.  Maybe it's just me, but I thought Clinton's political skills, intelligence, and stamina were very much in evidence.  She would not only perform well against candidate Trump but perhaps send him over the edge to the point where even Republicans would vote for her, or, if they could not bear to cast a vote for a Democrat, they would not vote and perhaps even stay home, which would affect not only the presidential vote but down-ticket Republican candidates. 

Further, the GOP "conservatism" of today quite obviously does not involve "respect for institutions and commitment to reasoned, incremental change" and has not for quite a number of years.

You say:

Liberals who claim that Trumpism is the natural outgrowth, or logical conclusion, of conservatism or Republicanism are simply wrong. Edmund Burke is not the grandfather of Nigel Farage. Lincoln is not even the distant relative of Trump.

You are wrong, Michael. The members of the so-called "center" of the GOP, who no longer have an influential voice in the party, stayed silent through the worst of the excesses perpetrated by Republican members of Congress, thus giving them free rein to vote for their extremist agenda, with the result that the two candidates who now lead in the polls are Trump and Cruz.

Two quotes come to mind:

Silence is the voice of complicity.  (Fr Roy Bourgeois)

For they sow the wind, and they shall reap the whirlwind.  (Hosea 8:7)