Earlier this month, we noted that Donald Trump's polling surge and lead -- only two weeks old at the time -- tracked with the surges seen by Rick Perry and Newt Gingrich in the 2012 cycle. With another few weeks under his belt, we can update the chart in that post to show that Trump's pattern no longer matches Perry and Gingrich.

That could change, of course. Trump's about four or five days out from where Perry and Gingrich dropped off, but there haven't been many polls recently.

It is also possible that it won't change.

Fox News has been polling on Trump longer than most media outlets, and has the polls closest to either side of the first Republican debate. The polling over time pretty much mirrors the graph above (and, we'll note, contributes to the data in the graph above). Trump rose sharply, and now is dipping slightly among a number of demographics. That's in comparison to Jeb Bush, who stayed pretty flat until the debate, and then dropped off.

The trend for each since June:

It's worth pointing out that the lead Trump enjoys is fairly even across all groups. When you compare where he leads with who turned out to vote in the Iowa and New Hampshire primaries, his leads are not just among groups who turn out less frequently.

Trump runs best among those with no college degree; the worst among those with degrees. Each group was about half of the electorate in Iowa; those with degrees turned out a bit more in New Hampshire.

The question is: Why is he doing so consistently across those groups? Is it because the field is splintered and the media attention he is attracting is peeling enough support from each group to put him in the lead? Is it because his message attracts a lot of support, regardless of how often he appears in front of a camera?

If the latter were the case, we might expect Trump to be among the most preferred candidates as voters' second choice. On that metric, he's consistently trailed Bush -- and, as of the most recent poll, Marco Rubio.

Not to mention that he is also the candidate most likely to be identified as someone for whom primary voters would never vote.

Can Trump sustain his current poll numbers? It seems so, though if the cameras turn away that may change. Can he sustain his lead? With 17 candidates running, yes. But 17 candidates will not be running forever.