If history is any guide (and it has not always been one this election cycle), support for Johnson and Stein will ebb over the next three months.

Supposedly serious Independent or third party nominees like John Anderson (1980) and Ross Perot (1992) saw their poll numbers slide in the final months of those campaigns as voters decided to cast their votes for someone who could win the White House. That same dynamic could well occur again (Perot’s numbers in 1996 and Nader’s in 2000 remained more stable.)

The Greens probably will attract a handful of Bernie Sanders supporters, but Stein’s (and her party’s) agenda is way too far to the left to attract mainstream supporters who otherwise would support Clinton.

And while Johnson’s decision to add Weld to his ticket surely reflects his effort to move the Libertarians to the political mainstream, that party spends as much time arguing internally about what it stands for as it does wooing general election voters.

As long as the Libertarians and Greens seem irrelevant and outside the political mainstream to the average voter, they will not be in the electoral conversation.