His numbers haven't been constantly increasing. He has been keeping steady at the same plurality while the split field has made everyone else be behind him.
Umm, no?
Nationally, he was polling in single digits up till mid-June. Then he was in the teens until around mid-July. Now he's in the mid-twenties. Unless your math is fuzzier than The Hair, that's a steady increase.
See graph here.His aggregate numbers have dipped slightly in the last week, but still above 20% and more than twice the next closest challenger.
Remember when it looked like Bush/Walker and everybody else? Well now it looks like Trump and everybody else. Carson, Kasich and Fiorina have emerged out of the deadweight tier into at least also-ran tier, while Rand Paul, Mike Huckabee and Chris Christie are plummeting into obscurity.
Now, will his numbers plateau in the twenties, and as other challengers drop out, will their votes coalesce around an anti-Trump? Quite possibly. But for now, yes Trump's numbers have been steadily increasing over the last two months.
@smjjames: China. Shanghai index dropped almost 9% last week, so markets everywhere else have been following suit. Which as I've talked about before in the AsiaPol thread, is ridiculous. The Chinese markets are almost pure speculative markets -- it's like going on a panic sell because your favorite World of Poker champ had a bad round of Texas hold'em.
EDIT: Ninja'd. Though, to reiterate an oft-used line: The stock market is not the economy, and the economy is not the stock market. The fundamentals of the Chinese economy are still stable. It's the absurdity of modern market capitalism -- "OH NOES CHINA ONLY GREW 7% LAST QUARTER SELL SELL SELL". While almost every nation on Earth would love to have a 7% GDP growth, people see something wrong because China had been growing at 10%+ for years, which was simply unsustainable and potentially far more worrisome than shallowing out the growth curve.