Michigan, Georgia top hot battlegrounds for 2026

• The contests will test both parties' messaging and enthusiasm two years into President Trump's second term, and are likely to feature candidates who could be in play as 2028 presidential contenders.

Driving the news: Peters' announcement puts Michigan at the center of Democrats' difficult path to winning back the 100-seat Senate, where Republicans now hold 53 seats.

• Democrats have been preparing to defend Peters' seat, but now they'll have to do so without the two-term senator on the ballot.
• Sen. Jon Ossoff (D) will be seeking to keep his seat in perennial battleground Georgia.
• Both Senate races in states that Trump won in 2024 are widely viewed as competitive — and a flip to Republicans in either race could help the GOP nail down a majority in the chamber for years.

State of play: Peters' announcement prompted a domino effect of prominent Democrats expressing interest in the seat.

• Former Transportation Secretary Pete Buttigieg, widely considered a possible 2028 presidential contender, is "taking a serious look" at the open Senate seat in Michigan, Axios reported Tuesday.
• Buttigieg, a former mayor of South Bend, Ind., now lives in Michigan and also has been seen as a potential candidate for governor.
• Michigan Lt. Gov. Garlin Gilchrist, who also has been floated as a possible candidate for governor, is also "seriously considering running" for the open Senate seat, a source close to Gilchrist told Axios.

Not running for the Senate seat: Michigan Gov. Gretchen Whitmer (D), whose term ends in January 2027. She's widely seen as a potential presidential contender in 2028.

• Michigan's Democratic Party has a "deep bench" to fill the pivotal open seats, party chair Lavora Barnes told Axios.

The other side: Peters walking away has "caused a complete roiling of everything, the whole Democratic side, both the governor's race and the senate race," said John Sellek, a public relations executive in Lansing, Mich., who used to work for Republicans.

• "It's opened the door to the possibility of affecting the governor's race instantaneously, that Buttigieg could theoretically slide over to the Senate race, which seems to fit his trajectory for wanting to be president someday," Sellek said.

Georgia's Senate race will be seen as a possible pick-up opportunity for Republicans in 2026.

• Gov. Brian Kemp (R-Ga.), another potential contender for the White House in 2028, has been floated as a possible challenger to Ossoff, but the popular Georgia governor hasn't indicated his plans.

Zoom out: Both states' gubernatorial races are still taking shape, with most possible candidates not saying publicly whether they intend to run.

• Both governor's races could serve as springboards for rising stars within each party. Being governors helped propel Kemp and Whitmer into national prominence.

What to watch: Even before Peters shocked Democrats with his announcement, Michigan was seen as a key measure of which way the political winds will be blowing next cycle.

• Besides the high-profile race for the governor, Michigan has open races for secretary of state, attorney general and several U.S. House seats.
• "What happens here in Michigan, very often, tells the story of what's happening in the country — and what could happen in the country," because Michigan's voting trends reflect those of the nation, Barnes said.

Go deeper: Scoop: Multiple House Dems eyeing Peters' Senate seat