... People keep saying we need 2/3 of the votes of the senate membership -- i.e. 67 votes -- to convict Trump. That's not what the constitution says. What the constitution says is that it takes 2/3 of the votes of those present.
If every senator were present, that would be 67 out of 100, but it's a mistake to assume 100 senators will be present ...
Sorry, but I do not believe that you are entirely correct.
While you are correct in what the US Constitution has to say about '2/3 of the Senators present'.
But it is my understanding that according to the rules of the Senate, that unless a senator has some terribly important reason for being absent, then all 100 of the senators must be present when the Senate is going through a Presidential impeachment trial.
As such, it will take at least 67 senators to convict Trump.
It's certainly possible there is such a senate rule. I'm not aware of that rule, but I'm not aware of many things.
It would be helpful if you could locate the place where this is rule is stated (if it is indeed a rule which is set down somewhere, and not just an assumption some people are making about what the rules are). Could you, or someone, try to locate this rule and then quote it in a comment for the rest of us to see?
As a small bit of help, here are what appear to be
the official senate impeachment rules. But my quick skimming of these rules did not turn up anything like what you are saying.
Quite the opposite, in fact; the wording of these rules, like the wording of the constitutional passage, refers consistently (in regard to the administering of the oath senators are required to take as well as in regard to the vote on whether to convict) to
members present. I do not see anywhere in these rules where it says all members will be present or that all members are required to be present. From the actual wording of these rules, it looks to me like the rules do not assume, require, or expect that all members will be present.
(Unfortunately this is a pdf document so I am unable to do a quick copy-and-paste of the text I'm referring to, and don't have time at the moment to type out the relevant portions. But I have provided the link so you can examine these rules for yourself.)
If the constitution and these rules are indeed the official rules regarding impeachment, that means it does not take 67 votes to convict. It takes 2/3 of the members present for the trial, whatever that number turns out to be.
It is likely that, normally, the great majority of senate members would want to take part in such an important senate proceeding. But it is by no means required. It is by no means guaranteed. And really, regarding impeachments, they occur so infrequently that we should not assume any impeachment is normal.
I think this is an extraordinary one, and it may be a time where a number of Republican members might prefer not to take part and not to have to cast a vote either to acquit or to convict if they think they can get away with it. If Democrats actually want to get a conviction I think they'd be strategically smart to quietly try to convince those Republicans members of the advantages of their boycotting the proceedings. (And if McConnell really would like to see Trump convicted in order to get him off the neck of the Republican party, as he seems to have indicated, McConnell would be smart to let those Republican members he's fine with their skipping out on the proceedings and will not penalize them for doing so.)
There may be possible penalties Chuck Schubert and Mitch McConnell could choose to impose on members who refused to attend the impeachment, but there is nothing in the rules I can see which says they have to make that choice. Senators are free to skip out on senate proceedings, including impeachments, if they choose, and there is no requirement that they be penalized for doing so. The current impeachment is an exceptional occurrence where almost everyone except Donald Trump might benefit by their making that choice.