How large of a Clinton win is needed to "send a message?"

[Virginiá]

At least six or seven.

But the best “message” would be Democratic control of the WH, Senate and House.

Pretty much. This idea of 'mandates' is outdated. Republicans don't care about it (and I doubt Democrats do anymore either), and if they have any power to impede Clinton/Democrats, they will use it as much as possible, no matter how much they screw things up, just like with Obama.

The only mandate I will see is if Democrats win back everything, in which case the filibuster should be changed so we can actually do something for a change.

[RINO Tom]

If anything, a massive Clinton win with nonexistent downballot coattails sends the biggest message. It's a rejection of Trump specifically, rather than something that can be spun into a rejection of the Republican Party or American conservatism more broadly.

[Erc]

If anything, a massive Clinton win with nonexistent downballot coattails sends the biggest message. It's a rejection of Trump specifically, rather than something that can be spun into a rejection of the Republican Party or American conservatism more broadly.

I'd disagree with that.  The biggest message would be a win with huge coattails, Portillo-style losses, etc., but by some miracle Mark Kirk holds on in Illinois.

That would be a true rejection of Trump and the 80% of Republicans who aid and abet him.  Not going to happen, of course.

[PresidentSamTilden]

I think 2 electoral votes will suffice.

You're running against the most unpopular candidate ever (other than yours), defending a 2 term incumbent, with a fairly weak economy. A candidate you've pretty much been pumping up your base to hate for like 15 years. And you lost??

In addition, it would really underscore that GOP post 2012 memorandum, or whatever it was called. The demographics for a white nationalist type of party just aren't there. Unless they can change and appeal to other groups, they'll never win a presidential election again.

[Ogre Mage]

The only mandate I will see is if Democrats win back everything, in which case the filibuster should be changed so we can actually do something for a change.

For most executive branch and judicial nominations the filibuster change has happened already.  So long as we control the U.S. Senate, President Clinton should be able to put her team in place.  The federal agencies can craft rules and regulations which will help move the policy ball for us.  It obviously would be better if we controlled both the Senate and House so we could act legislatively, but that's unlikely.  I think a lot will have to be attempted through federal agency rules and Presidential executive order.

And it goes without saying that control of the judiciary is critical.  The filibuster is still allowed for Supreme Court nominations (but not the lower courts).  There is a fair chance Senate GOP filibuster abuse will force Senate Democrats to change this as well in the near future.