“The main point, then, is that Congress can apply the 14th Amendment disqualification to Trump by majority vote.”
Impeaching Donald Trump after he's left office is NOT unconstitutional. Other officials (though never an ex-president until Trump) have been impeached after leaving office. Not only is that precedent, but common sense also comes into play: if officials couldn't be impeached after leaving office, there would be nothing preventing them committing “high crimes and misdemeanors” shortly before the end of their terms and leaving before they could be held accountable.
However, in the crucial court of public opinion such logic doesn't matter because too few average observers can appreciate such subtlety of constitutional law. Most people will just look at you crosseyed and say, “You mean you're gonna impeach him when he's already out of office? How stupid is that?”
So once again, Trump has been impeached and once again, spineless and principle-free Republican lawmakers will fail to convict. This will give the Inciter-in-Chief yet another victory to crow about; it will only bolster his myth among the true believers, making him even harder and more dangerous to stand up to in the future.
Democrats should have avoided impeachment altogether. The so-called “unconstitutional” nature of impeaching a former president – while wrong – provided easy cover for Republican House members not to impeach and Republican Senators not to convict. It should have been presented as a simple matter of his having violated the Constitution. It's right there in the 14th Amendment:
No Person shall be a Senator or Representative in Congress, or elector of President and Vice-President, or hold any office, civil or military, under the United States, or under any State, who, having previously taken an oath, as a member of Congress, or as an officer of the United States, or as a member of any State legislature, or as an executive or judicial officer of any State, to support the Constitution of the United States, shall have engaged in insurrection or rebellion against the same, or given aid or comfort to the enemies thereof.
And, according to lawfareblog.com (and others) finding Trump guilty of violating the 14th Amendment would require only a simple majority, rather than the two-thirds Senate vote required to convict him in his impeachment trial.
But no, once again, Democrats have apparently let a little success (the election of Biden & their new slim majority in the Senate) cloud their judgment. In their zeal to punish Trump, they've ignored the much easier way to do it (applying the 14th Amendment) and have opted instead for the near-certain failure of impeachment.
At least I get to join the company of the celebrated Will Rogers by saying, “I am not a member of any organized political party. I am a Democrat.”