He was the Democratic nominee for the United States Senate for Missouri in 2016, losing the election to Republican incumbent Roy Blunt.

[2] After the Senate election, Kander founded an organization called Let America Vote, a campaign dedicated to addressing alleged voter suppression.

[14][15] He graduated from Bishop Miege High School in 1999, where he played on the baseball team[16] and was a nationally competitive debater who won two state championships.

[22] While serving, his main responsibilities included investigating groups and individuals suspected of corruption, espionage, drug trafficking, and facilitating Al Qaeda and the Taliban.

[23] When he returned home, Kander took a position as an instructor at the Missouri Army National Guard's Officer Candidate School at Fort Leonard Wood.

[26] In 2010, he was named one of ten finalists for the Army Reserve Association's Major General Strom Thurmond Outstanding Junior Officer of the Year Award.

[28] Heartland Democrats of America (HDA) was a political action committee founded in 2005 in Kansas City, Missouri, by Kander and his wife, Diana.

[32] Notable supporters included current and former state and city elected officials, along with national figures, such as Terry McAuliffe, the former Democratic National Committee (DNC) chairman and former Virginia governor; George Lakoff, an author and professor at the University of California, Berkeley; John Halpin, a senior fellow at the liberal Center for American Progress; and Mark Talisman, an author, Democratic activist, and president of the Project Judaica Foundation.

[23] In 2010, Kander worked with Republican colleague Tim Flook to pass the first major ethics reform bill in Missouri since 1991.

By contrast, Kander opposed harsher voter identification rules, instead focusing on reforming the state's campaign finance laws.

He admitted this could be "an uphill battle' given that Missouri has had some of the weakest ethics laws in the country and Republicans had supermajorities in both chambers of the state legislature.

[44] On February 19, 2015, Kander entered the race to represent Missouri in the United States Senate against Roy Blunt, the Republican incumbent.

[47] In September, Kander's campaign received national attention when it released an advertisement explaining his support for gun control measures.

[50] In response to this, Blunt campaign began attacking Kander for being a national co-chair for presidential candidate Hillary Clinton.

[46] During the campaign, Kander received endorsements from Americans for Responsible Solutions,[51] Daily Kos,[52] the League of Conservation Voters,[53] Planned Parenthood Action Fund,[54] and the Sierra Club.

[2] On June 25, 2018, Kander announced that he was running for mayor of Kansas City in 2019 to replace incumbent Sly James, who was term limited.

[58][59][18][60] Speculation about his presidential ambitions had been fueled by his frequent visits to the early primary states of Iowa and New Hampshire,[61] and Kander had suggested he would consider exploring a bid after the 2018 midterm elections were finished.

[68] He hosts the Wonder Media Network podcast Majority 54 with Jason Kander & Ravi Gupta: he and his guests explore how Democrats can talk about divisive issues with people who voted for Donald Trump.

[69] In 2018, he published his first book, Outside the Wire: 10 Lessons I've Learned in Everyday Courage, reflecting on the period of his time in the military, to when he launched his first political campaign.

[72][73][74] Kander has also lent his support to other Democrats running for office, such as Jon Ossoff,[75] Phil Murphy,[76] Conor Lamb,[77] Stacey Abrams,[78] and Kyrsten Sinema.

[80][81][82] Notable members of its advisory board include human rights activist Martin Luther King III, actor Bradley Whitford, and former White House officials Josh Earnest, Jon Favreau, and Dan Pfeiffer.

[83] In his capacity as president of Let America Vote, Kander also serves as chairman of the DNC's Commission on Protecting American Democracy from the Trump administration.

The NRA Political Victory Fund gave Kander an "F" rating and spent nearly $1 million against him in 2016 (the most money against any candidate that year outside of Ohio).

He has proposed changing the 30-hour workweek used to define full-time employees, allowing cheaper plans for people who do not require medical care, and repealing the long-delayed Cadillac tax.

[85] Kander was critical of Republican senators who refused to meet with Supreme Court nominee Merrick Garland, citing it as an example of Washington dysfunction.

[85] Kander supports the 2015 United States Supreme Court ruling in Obergefell v. Hodges that deemed the Defense of Marriage Act unconstitutional.

[85] He is opposed to closing the detention camp at Guantanamo Bay but also voted against a measure to prevent Missouri from housing, transporting, or providing medical care to any prisoners suspected of terrorism.

[103] On May 19, 2023, Georgetown University bestowed upon Kander an honorary doctorate in humane letters in conjunction with his delivery of that year's commencement address.