Clinton’s problem with young voters is that while few of them can remember the relative prosperity of Bill Clinton’s presidency, many of them associate her with a corrupt, dysfunctional political system. Stanley Greenberg, a pollster who worked for Bill Clinton, told the Los Angeles Times this summer, “They think she’s a typical politician . . . aligned with the elites . . . aligned with the big money and Wall Street.”

The strength that Johnson shows in Western states is also impressive, and it confirms that his presence in the race is more harmful to Hillary than to Trump. Earlier this month, the Washington Post conducted in-depth individual polls in all 50 states. Their polls were revealing in contested Western states. In a two-way contest, Hillary leads in Arizona by one point, in Colorado by two points, and in Nevada by five points. In a four-way race that includes Johnson and Stein, Trump leads by two points in Arizona, ties in Colorado, and is down three points in Nevada. Even New Mexico, Johnson’s home state, is much more competitive in a four-way race: Hillary leads by 14 in a two-way race and only eight in a four-way race.

Of course, it’s entirely possible that Johnson and Stein have hit their ceiling of support. Neither candidate is likely to be in the presidential debates, which since 2000 have required any candidate participating to average 15 percent support in major polls. That caps their exposure to an electorate in which over half of potential voters know little or nothing about either of them. In addition, third-party candidates routinely lose support in the home stretch of a campaign when some people decide that voting for a non-major-party nominee could be a “wasted” vote.