I will not be voting for Donald Trump for president. This is not a decision I make lightly, for I am a lifelong Republican. But Donald Trump does not reflect historical Republican values nor the inclusive approach to governing that is critical to healing the divisions in our country.

When the primary season started, it soon became apparent that, much like Sen. Bernie Sanders (I-Vt.), Mr. Trump was connecting with many Americans who felt that their voices were not being heard in Washington and who were tired of political correctness. But rejecting the conventions of political correctness is different from showing complete disregard for common decency. Mr. Trump did not stop with shedding the stilted campaign dialogue that often frustrates voters. Instead, he opted for a constant stream of denigrating comments, including demeaning Sen. John McCain’s (R-Ariz.) heroic military service and repeatedly insulting Fox News host Megyn Kelly.

With the passage of time, I have become increasingly dismayed by his constant stream of cruel comments and his inability to admit error or apologize. But it was his attacks directed at people who could not respond on an equal footing — either because they do not share his power or stature or because professional responsibility precluded them from engaging at such a level — that revealed Mr. Trump as unworthy of being our president.

The speaker’s office delivered a swift and forceful response “Neither Speaker Ryan nor anyone on his team has ever asked for Donald Trump’s endorsement,” Zack Roday, Ryan’s campaign spokesman, said in a statement. “And we are confident in a victory next week regardless.” Indeed, it would be highly unusual for Ryan to solicit Trump’s endorsement — not just because of their many political differences, but because Ryan doesn’t need Trump’s help to win his district.

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With all this in mind, Trump’s decision to flex muscle at Ryan would seem strategically shortsighted. The nominee appeared eager to demonstrate who holds the power in their forced and often combative partnership. But the most likely outcome next Tuesday is a lopsided Ryan victory, which, in the wake of today’s public quarrel, will leave Trump — not the speaker — looking weak.

Taken as a whole, Trump's economic plan is disastrous. Large tax cuts without even larger spending reductions mean explosive deficits and debt. Massive interference with free trade means a far less productive economy. The few sensible elements -- tax reform and regulatory reform -- cannot plausibly undo the damage of the other proposals.

Donald Trump’s problems inside his own party were compounded Monday when 50 senior national security officials who have served under GOP administrations stretching back to that of Richard Nixon warned he “would be the most reckless president in American history.”

"None of us will vote for Donald Trump," said the letter, in which some of the most influential players in defense policy warned he would be "dangerous" in the Oval Office.

Those who signed include Michael Chertoff and Tom Ridge, both former secretaries of Homeland Security, as well as John Negroponte, who served as director of national intelligence.

“Mr. Trump lacks the character, values, and experience to be president,” the officials warned. “He weakens U.S. moral authority as the leader of the free world. He appears to lack basic knowledge about and belief in the U.S. Constitution, U.S. laws, and U.S. institutions, including religious tolerance, freedom of the press, and an independent judiciary.”