Sen. Susan Collins (R-Maine) speaks with reporters on Capitol Hill in Washington. (J. Scott Applewhite/Associated Press)

Sen. Susan Collins (R-Maine) joins — among others — Sens. Ted Cruz (R-Tex.), Mark Kirk (R-Ill.), Lindsey Graham (R-S.C.), Mike Lee (R-Utah) and Ben Sasse (R-Neb.); 50 foreign-policy gurus who have served in various administrations; the Harvard Republican Club (!); Govs. Larry Hogan of Maryland and Charlie Baker of Massachusetts; former presidents George H.W. Bush and George W. Bush; Mitt Romney; Reps. Adam Kinzinger (R-Ill.), Scott Rigell (R-Va.) and Richard Hanna (R-N.Y.); Meg Whitman; Hank Paulson; and top aides to Jeb Bush, New Jersey Gov. Chris Christie and Sen. John McCain (R-Ariz.) in refusing to back Donald Trump.

Collins argues, “My conclusion about Mr. Trump’s unsuitability for office is based on his disregard for the precept of treating others with respect, an idea that should transcend politics. Instead, he opts to mock the vulnerable and inflame prejudices by attacking ethnic and religious minorities.” She gives the back of the hand to the pleas for party loyalty: “I revere the history of my party, most particularly the value it has always placed on the worth and dignity of the individual, and I will continue to work across the country for Republican candidates. It is because of Mr. Trump’s inability and unwillingness to honor that legacy that I am unable to support his candidacy.”

Whatever the percentage of Republicans who defect from Trump turns out to be, the repudiation of a party’s nominee by so many (and we likely will see many more) prominent elected and former officials and campaign veterans should be heartening to Republicans of good conscience and the country as a whole. Not all Republicans have lost their minds. Not all Republicans have become self-deluded shills repeatedly arguing that he now has “pivoted” to something approaching a normal candidate. Not all Republicans are willing to put the country at risk out of fear of offending a noisy, nasty element in their base. This is, in the midst of the most appalling presidential candidacy of either major party in the history of the republic (name someone worse, can you?), reason for celebration.

The exodus may have several ramifications.

First, it makes those who have gone along with the Trump charade either enthusiastically (e.g. Newt Gingrich, Christie, Sen. Jeff Sessions, Rudy Giuliani, talk radio personalities Hugh Hewitt, Rush Limbaugh, Laura Ingraham and Sean Hannity) or reluctantly (e.g. House Speaker Paul Ryan, Sen. Marco Rubio) look even worse. The Trump cheerleaders and apologists had plenty of examples of intellectual honesty and political courage, but they had not the strength of character or judgment to join the sensible minority in their party. They were not even in the top 10 percent, if you will, of Republicans. The more Republicans who join the flight from Trump, the worse the hangers-on look. Really, why should conservatives or any Americans pay the latter much heed on critical issues of judgment in the future?

Second, Hillary Clinton should understand the rare opportunity presented to her. She can grab the GOP votes and campaign donations, race to a landslide and then ignore the outpouring of bipartisan support. No one would be surprised. However, as both a policy and political matter, she would be wise to incorporate those sensible GOP voices into her administration, put conscientious figures in office or rely on their advice and aim for a broad unity government that can reach consensus on some major issues, especially in the national security realm. It may permanently remake the political landscape in the long run. In the short run, it may be critical to avoiding gridlock and minimizing chances of another failed presidency.

If she wants to be a successful president, not simply a landslide winner, Clinton cannot revert to governance directed at a narrow base of supporters. That requires self-restraint (e.g. on spending), prioritization (e.g. racking up wins on consensus items), courage (e.g. breaking with President Obama on some foreign-policy issues) and realism (e.g. Obamacare in its current form cannot keep its promise of affordable care).

Finally, the patriotic exodus of Republicans offers the chance to improve the tone and level of discourse. The talk radio and Fox News set that dabbles in hysteria, conspiracy-mongering and resentment will be on the losing side, the embarrassing side of the election. That affords the rest of the political spectrum the opportunity to behave more civilly, rationally and humanely. Don’t be like those guys — the losing Trumpkins. Be better.

The flood of GOP defectors almost restores one’s faith in the party of Lincoln. It’s not the entire party — let alone the whole electorate — that has departed from its senses and lost track of the fundamental principles that have always made America great. Maybe it took someone as heinous as Trump and as intellectually and morally flawed as his fanboys to remind us how tentative is our attachment to self-governance and how decent are many fellow Americans, ones willing to stand up to a demagogue and charlatan. If so, it will — almost — have been worth enduring this dreadful election cycle.