- Senate Class 3 (up in 2028) features senators elected in 2022 — a Democratic wave year — meaning several Democrats hold seats in states that have since drifted Republican.
- Susan Collins (R-ME) has defied her state's D+10 lean in every election cycle since 1996, making her one of the most studied examples of personal-vote politics in modern Senate history.
- Class 3 includes several Western and Southwestern Democratic incumbents whose margins will depend heavily on whether 2024's Hispanic voter shift proves durable or reverses.
- Planning 2026 resource allocation while considering 2028 Class 3 math is a strategic necessity for both parties — Senate majority control requires managing 3-cycle pipelines simultaneously.
- The 2028 Senate map is historically favorable for Republicans based on which states' seats are up — but 2026 outcomes will determine whether Republicans start 2028 needing to defend an expanded majority.
Key Senate Class 3 Seats: Early 2028 Outlook
| State | Senator | Party | State Lean | Early 2028 Rating |
|---|---|---|---|---|
| Georgia | Raphael Warnock | D | R+2 | Toss-up |
| Arizona | Mark Kelly | D | R+1 | Toss-up |
| Maine | Susan Collins | R | D+7 | Lean R / Competitive |
| Illinois | Tammy Duckworth | D | D+15 | Safe D |
| Vermont | Bernie Sanders | I/D | D+18 | Safe D |
| Idaho | Mike Crapo | R | R+26 | Safe R |
| Oklahoma | Jim Inhofe seat (successor) | R | R+23 | Safe R |
Why the Class 3 Map Matters Before 2026 Is Even Over
Senate watchers are already beginning to discuss the Class 3 map — the 34 Senate seats up for election in 2028 — because what happens in 2026 determines the starting point for 2028 senate control. If Democrats flip the Senate in 2026, they go into 2028 defending a majority; if Republicans hold it, the Class 3 map is the next opportunity. The Class 3 map is structurally more favorable to Democrats than either the 2024 (Class 2) or 2026 (Class 1) cycles. Republicans are defending more seats in blue-leaning or competitive states, particularly Maine (Collins, D+7 state), while Democrats have fewer exposed incumbents in deep-red territory than they did in 2024.
The most competitive Class 3 seats in 2028 are in Georgia and Arizona — states that have shown genuine electoral competitiveness in recent presidential and Senate elections. Raphael Warnock has now won three consecutive statewide elections in Georgia (two in 2021, one in 2022), establishing a genuine political brand and a mobilization infrastructure rooted in the Atlanta metro. But Georgia remains an R+2 presidential state, meaning Warnock's wins are a product of exceptional candidacy and organization rather than a durable Democratic structural advantage. A strong 2028 Republican recruit in Georgia would immediately make the race competitive regardless of Warnock's individual strength.
Arizona presents a similar picture for Mark Kelly. Kelly has won twice in a state that is drifting slightly rightward at the presidential level (Trump won AZ narrowly in 2024 after Biden narrowly won in 2020). Kelly's military background, moderate positioning, and strong constituent services record give him incumbency advantages beyond what the D+1 partisan lean suggests. But the structural risk is real, and 2028 presidential-year turnout brings more irregular voters to the polls — which in Arizona means more Republican-leaning casual voters who don't participate in midterms.
Susan Collins in 2028: The Perennial Question
Susan Collins has now survived three Democratic wave cycles — 2006, 2018, and 2020 — in a state that has grown consistently more Democratic at the presidential level. In 2020, she won 51-42 against Sara Gideon despite facing a $70 million Democratic spending effort, the most expensive Senate race in Maine history at that time. She did so by running ahead of Trump by 28 points in the same state, demonstrating that Maine voters are willing to split tickets for a senator they trust on bipartisan issues.
By 2028, Collins will be 71 years old. The retirement question — which has circulated in Maine political circles since at least 2020 — will be unavoidable. If she runs for a sixth term, the race will follow the familiar pattern: Democrats invest heavily, Collins runs as a pragmatic independent-minded Republican, and the outcome hinges on whether Maine's tradition of ticket-splitting survives the nationalizing pressure of a presidential year. If she retires, an open Senate seat in a D+7 state becomes one of the top Democratic pickup opportunities of the entire 2028 cycle, with implications for Senate control that would cascade through the remainder of a potential second Trump term (if applicable) or the start of a new administration.
What This Means for 2026
The Class 3 preview matters for 2026 because it shapes how aggressively each party will fight the current cycle: knowing that the 2028 map favors Democrats even more than 2026, Republicans have added incentive to maximize their Senate majority now rather than counting on a favorable 2028 defense. Warnock and Kelly's ability to entrench themselves as incumbents in 2022 and 2024 respectively gives Democrats their best platform for a long-term competitive Senate position in Sun Belt states.
