House Speaker Paul D. Ryan (R-Wis.), left, and Senate Majority Leader Mitch McConnell (R-Ky.) walk to a Senate Republican policy luncheon in Washington on Nov. 3, 2015. (Andrew Harnik/Associated Press)
Opinion writer

In the wake of Donald Trump’s racist attack on Judge Gonzalo Curiel, Sen. Lindsey Graham declared, “This is the most un-American thing from a politician since Joe McCarthy. If anybody was looking for an off-ramp, this is probably it.”  He continued, “There’ll come a time when the love of country will trump hatred of Hillary.”

As a public service, I offer the following, to be used by any Republican officeholder or candidate who has come to his or her senses:

Thank you for coming here today. When the 2016 presidential race began, I made clear that Donald Trump was not my first or even my 17th choice. For the GOP to succeed, we need a hopeful, inclusive and realistic agenda. I strongly believed Mr. Trump did not have these qualities. I disagreed with his views on trade, immigration, foreign policy and entitlements, among other things.

Then the GOP primary voters spoke. Because I have been a lifelong Republican and owe my political career to fellow Republicans, I felt it was my duty to support the nominee of the party. I thought that perhaps Mr. Trump’s behavior during the primary season might have been an act to garner free media attention. I thought he might get quality advisers to help him in the general election. I thought he might not actually harbor animus toward women and minorities. I thought in discussions with Republicans on the Hill he might have chosen simply to adopt their agenda and forgo fanciful schemes.

I was wrong, and for that I want to apologize to the voters. All of my concerns about his preparation, policy stances, disrespect for fellow Americans and lack of appreciation for our democratic system have deepened since he locked up the nomination. He has attacked fellow Republicans, made a racist accusation against a federal judge and declined to renounce idiotic policy positions.

I now realize that I let party loyalty cloud my judgment. I failed to remember when I chose to endorse him that character, not transitory political positioning, is the critical quality to look for in a president. I did not anticipate that Hillary Clinton would run on a center-right foreign policy platform or that Trump would continue to display ignorance and incoherence about the duties of the commander in chief. I am embarrassed to admit that I was willing to overlook bigoted and disgraceful comments and actions directed at minorities, women, prisoners of war, and the disabled. Again, I was wrong.

Mr. Trump, actually, has opened my eyes. He reminded me that we can find areas of agreement and cooperation not with him but with rational Democrats. He underlined for me the importance of respect for an independent judiciary. He also revealed that too many of my fellow Republicans are unwilling to call racism by its name.

I therefore have no choice but to withdraw my support for Mr. Trump for president. President John F. Kennedy famously said, “Sometimes party loyalty asks too much.” In this case, party loyalty would require I support a man who is temperamentally and intellectually unfit for office, and whose views are antithetical to my own and even to the very concept of a free democracy that operates within the rule of law.

I will not campaign for or raise money for Mr. Trump. I will not attend the convention. I will vote my conscience in November and hope there is an alternative, true conservative on the ballot.

I do not know if this action will hurt or help me politically. I understand some of you may hold my initial endorsement against me. I respect that view. But I think it is also important to recognize we are mortals, not angels. We make mistakes. Mine was in allowing party loyalty to override common sense and the precepts of our Judeo-Christian heritage that instruct us to treat others as we would wish to be treated. Thank you for hearing me out.

There. It’s not so hard to explain an initial misjudgment, nor to reverse course once it becomes apparent you were wrong. What is inexcusable is to commit a grievous mistake, recognize it as such and allow cowardice or pride to prevent you from correcting the mistake. C’mon, Republicans, how about it?