These young voters have had few years in which to build up party loyalty, and they have been switching around. In 2008, voters under 30 went 66 percent for Barack Obama. But the current Quinnipiac survey shows under 35s voting only an average of 51 percent for Clinton when matched against Republicans Jeb Bush, Marco Rubio and Donald Trump.

Many young people are apparently open to voting Republican — but not for Trump. For the Millennial generation, it appears, Trump is yesterday’s news.

Why should that be so? The best explanation I can come up with is that Trump’s signature issues, the issues on which he has sparked controversy — immigration and, often mentioned in the same breath, trade — are issues that have been declining in salience in recent years.

They still animate older voters, who have been paying attention for some time. But for younger voters, they’re yesterday’s news.