President Biden won the Democratic caucuses in Iowa, according to The Associated Press, the first of 16 Super Tuesday contests he is expected to dominate as the 2024 presidential campaign shifts fully toward the general election.

Mr. Biden has faced only token opposition from Representative Dean Phillips of Minnesota and the self-help author Marianne Williamson, sweeping them aside in all of the primary contests so far.

Despite widespread angst within the party about his ability to rally the coalition that powered his 2020 victory, Mr. Biden appears on the verge of again emerging as the consensus Democratic choice. His planned State of the Union address on Thursday serves as an unofficial kickoff to a likely November race against former President Donald J. Trump.

The president’s campaign team views Tuesday’s contests as a moment when the nation will increasingly begin to focus on the choice between the president and Mr. Trump, his predecessor, who is also expected to build an insurmountable delegate advantage over his last Republican challenger, former Gov. Nikki Haley of South Carolina.

Aside from a perfunctory challenges and angst about the impact of the war in Gaza on last week’s primary election in Michigan, there has been little drama surrounding Mr. Biden’s bid for renomination.

The only state voting on Tuesday with a modicum of mystery for Mr. Biden appeared to be Minnesota, where Muslim Democrats and progressives sought to duplicate the Michigan effort to persuade voters to cast ballots for “uncommitted” in protest of Mr. Biden’s position on Israel.

North Carolina is the only state set to be a battleground in the general election that held a primary on Tuesday. While the Biden campaign has not devoted the attention and resources to turning out primary voters on Tuesday that it did in South Carolina, Nevada and Michigan, which have already held their contests, the state has emerged as one of the campaign’s top targets for November. The Biden team has dispatched staff members there weeks before it has done so for other key states like Georgia.

The states with the largest delegate hauls for Mr. Biden on Tuesday are Texas and California, though Massachusetts and Virginia are also expected to deliver Mr. Biden their entire slates. Other states with primaries on Tuesday include Alabama, Maine, Oklahoma, Tennessee, Arkansas, Colorado, Utah and Alaska. American Samoa also has a contest.