Cruz Iowas in Iowa. (AP Photo/Paul Sancya)

Ted Cruz is a natural for the Iowa caucuses. He's a good campaigner, he's a stalwart conservative, he has grass-roots anti-establishment bona fides. In a smaller field, he'd probably have been leading in Iowa for a while now. As it is, he's had to wait his turn.

His number has just been called.

New polling from Quinnipiac University puts Cruz near the top of the field in the state with 23 percentage points -- inside the margin of error on Donald Trump's 25 percent. He's seen big spikes with a number of constituencies since Quinnipiac's last poll in the state a month ago.

Instead of us writing a thousand words about it, though, explore this.

Those blue lines rising up are Cruz. The red ones headed up less significantly are Trump. And those yellow lines shooting downward with a lot of energy are Ben Carson.

That's the story here, really. Ted Cruz is making big gains largely because Ben Carson is plummeting. We noted on Monday that the two were fighting over the same voters, but this poll makes that very clear. Carson's stumbling responses to foreign policy questions -- and the emergence of foreign policy as an issue -- have inspired his supporters to look elsewhere. They are looking to Cruz.

Cruz now leads all candidates among women -- a position he stole from Carson. Sure, his 21-point gain from tea party supporters is big, but tea party supporters aren't half of the voters. Cruz also likely gained from Bobby Jindal dropping out of the race, but those gains were ... more modest.

Of course, that big surge still has Cruz in second. Trump benefited a bit from Carson's stumble, too. Trump's base is also slightly more solid than Cruz's -- and much more solid than Carson's or Marco Rubio's.

That's a very, very important figure. When we wrote about the a Bloomberg poll last month, we noted that Trump's base of support was much more solid than Carson's. And: Voila.

One poll! It's early! Etc.! But Cruz was due a moment in the Hawkeye state, and it appears to have arrived.