Democratic lawmakers, strategists and possible presidential candidates gathered in Denver on Thursday for a two-day conference on where the party goes next, days after midterm elections that handed Democrats control of both chambers of Congress.

The conference, called What’s Next, isn’t an official party event. Majority Democrats, a new moderate group led by Representative Jake Auchincloss of Massachusetts, planned it before the vote, and the group’s political action committee, MD PAC, is paying for it, according to the group’s event page. Gov. Josh Shapiro of Pennsylvania, former Transportation Secretary Pete Buttigieg and Senator Cory Booker of New Jersey, all seen as possible contenders for the 2028 Democratic presidential nomination, are on the program, Al Jazeera reported.

The Associated Press, in a report carried by The Denver Gazette, called the midterms the party’s best electoral showing in half a century. Beyond Congress, Democrats won control of at least 12 more state legislative chambers. The new majorities take over the House and Senate in January, and the party has to decide how to use them against President Trump in his last two years in office.

Black office chairs surround a blue conference table that branches into three arrows pointing toward mountains against a textured yellow background.

Majority Democrats pitches itself as an alternative to two camps. One is an establishment that, in the group’s words, “sells mediocrity disguised as moderation.” The other is an activist left that “demands purity disguised as justice.” Its members, the group says, are “willing to challenge the establishment and break with their party” when that serves their constituents.

Some progressives say the group’s vision is too timid. They point to its support for a public insurance option it calls Medicare for Americans instead of Medicare for All. Representative Alexandria Ocasio-Cortez of New York and Senator Bernie Sanders of Vermont, two of the left’s best-known figures, aren’t among the published speakers, at a moment when the party’s 2028 argument has already started to pull in other directions.

Thursday’s opening program, according to the conference schedule, included a welcome from Denver’s mayor, Mike Johnston, and a talk by Bryan Stevenson titled “The Burden and Power of Hope.” The data analysts David Shor, Lakshya Jain and Charlotte Swasey were set to walk through what happened in the election. Then came a session called “How We Did It” with Rob Sand, Sandra Jauregui and James Talarico.

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Mr. Talarico, now the senator-elect from Texas, flipped a Republican seat. So did Josh Turek, the senator-elect from Iowa, who is also attending.

Others thinking about a White House run are there too. Representative Ro Khanna of California, who calls himself a long shot for the presidency, and Senator Chris Van Hollen of Maryland, who is weighing a 2028 bid, will join Senator Andy Kim of New Jersey on a panel called “The Trust Deficit.” Mr. Shapiro is scheduled to speak with Senators Elissa Slotkin of Michigan and Ruben Gallego of Arizona about the party’s next era.

The organizers said they picked Denver because of how much Colorado’s politics have changed over the past few decades. Interest was high enough that registration closed early and a waitlist opened, Denverite reported last week.

On Friday, Representative Hakeem Jeffries of New York, who is expected to become speaker of the House, is set to talk about the 120th Congress. Some on the left have questioned the party’s leadership. The conference closes Friday at the Mission Ballroom with a mainstage program titled “The Moral Majority.”