I'm seeing things like "For the first time, Trump now leads the average of national polls," complete with this view of the trend line at Real Clear Politics:
That's displaying the last 3 months. But if you back up and take the longest view, going back to last July, you can see that this is the 4th time Trump (more or less) caught up to Hillary:
Trump making up a lot of ground is not a new phenomenon. And the long view shows Hillary repeatedly reestablishing a lead. The graph exaggerates the range, showing us only what's happening in percentage points in the 40s. The 2 keep meeting at a point in the mid-40s, where neither has a majority, and Hillary breaks away and ends up above him. But don't lose your bearings: Since last August, she's barely ever emerged above 50% — on a couple days there in late March.
It is true that Trump is leading in the average for the first time, but only by 0.2, and he got very close to her at 3 other points. If I knew nothing other than this long term trend, I'd predict that Hillary would bounce back up again, that every time President Trump starts to look like a real possibility, Hillary is able to draw off enough people to push him back into the World of Dreams. From that retreat, he builds excitement again.
But I do know something more than that trend line. I know that Trump has the nomination sewn up and Hillary does not, and I think it's likely that the GOP convention will be a wonderful pro-Trump show and the Democratic convention will be a collision of conventional, boring efforts to plump up Hillary and pro-Bernie disruption. That makes me picture Trump's line ascending while Hillary's sinks.
Yet even if that happens, don't you think that over the long course of August, September, and October, she will crawl her way back, cross his line, and emerge the victor? From the down position, she'll be the scrappy fighter, who's fought so damned long for this prize.
And yet, if Trump rises high enough and maintains that position, the central argument against him — This isn't real! He's not normal! — will become unintelligible.