A Big Reason to Pay Attention to Iowa? New Hampshire.

The long road to the Republican presidential nomination begins tonight in Iowa, where voters will gather at their neighborhood precinct caucuses to cast the first votes of the 2024 election campaign.

Iowa may not have many voters or delegates, but the first-in-the-nation caucuses always attract a media frenzy. With the help of the national spotlight, Iowa voters have been surprisingly influential over the decades: A caucus win has sometimes been enough to propel candidates — think Barack Obama or Jimmy Carter — from a deep deficit or even obscurity to the nomination.

But tonight, Iowa voters seem likely to choose Donald J. Trump — someone they didn’t pick eight years ago, but who now appears poised for the largest victory in a contested Iowa Republican caucus.

Absent a polling meltdown, Mr. Trump’s victory would be one of the more impressive illustration of his dominance over the Republican Party. In 2016, Iowa voters rejected Mr. Trump in favor of Ted Cruz. And unlike most of the country, the Republican establishment in Iowa has not gone along with Mr. Trump. Yet he’s poised for an overwhelming victory anyway.