1980
What it would have taken
Counterfactual arithmetic from each state’s recorded popular vote. It measures how close the result was; it does not predict what voters would have done.
Illinois was the tipping point. Line up the states Reagan carried from widest margin to narrowest: Illinois’s 26 electoral votes are the ones that took Reagan to 281, past the 270 majority. Reagan carried it by 376,636 votes (7.93 points).
The cheapest set of Reagan’s states that would have given Carter a majority is these 17 states (listed in the table below) — 222 electoral votes. Reagan’s combined margin in these states was 1,458,732 votes.
A margin is overturned when more than half of it switches sides, so this path would have needed at least 729,379 Reagan voters to vote for Carter instead, in exactly those states. Had that happened, the count would have been Carter 271, Reagan 267.
| State | EV | Margin | Points |
|---|---|---|---|
| Massachusetts | 14 | 3,829 | 0.15 |
| Tennessee | 10 | 4,710 | 0.29 |
| Arkansas | 6 | 5,123 | 0.61 |
| South Carolina | 8 | 11,057 | 1.24 |
| Alabama | 9 | 17,462 | 1.30 |
| Mississippi | 7 | 11,808 | 1.32 |
| Kentucky | 9 | 17,857 | 1.38 |
| North Carolina | 13 | 39,383 | 2.12 |
| Delaware | 3 | 5,498 | 2.33 |
| New York | 41 | 165,459 | 2.67 |
| Maine | 4 | 17,548 | 3.36 |
| Wisconsin | 11 | 107,261 | 4.72 |
| Louisiana | 10 | 84,400 | 5.45 |
| Vermont | 3 | 12,676 | 5.94 |
| Michigan | 21 | 253,693 | 6.49 |
| Pennsylvania | 27 | 324,332 | 7.11 |
| Illinois | 26 | 376,636 | 7.93 |
| Total | 222 | 1,458,732 |
Margin = the winner’s votes minus the runner-up’s in that state. Points = that margin as a share of every vote cast there.
Flipping the winning path’s states plus Missouri, Connecticut and New Mexico but without Illinois (Reagan’s combined margin 1,443,526 votes) would have left nobody at 270: Carter 269, Reagan 269. A tie is not a win. The Twelfth Amendment would then have sent the choice to the House of Representatives, voting one vote per state delegation.
That costs less than the winning path above because it needs fewer electoral votes: Carter gains just enough to stop Reagan, not enough to win.
No single state Reagan carried was big enough to have elected Carter on its own.
Electoral votes in parentheses: the block each state cast for Reagan. This uses electoral votes only, not margins.
Nationally, Reagan received 43,903,230 votes and Carter 35,481,115, so Reagan finished 8,422,115 votes ahead of Carter (9.74 points). Reagan won the Electoral College 489–49.
How these are defined
- Flip
- Exactly what a click on the map does: the electoral votes a state cast for the candidate who carried it move to another candidate. District and faithless electors stay as cast.
- Margin
- The winner’s votes minus the runner-up’s in a state, from the state’s recorded popular vote. Points are that margin divided by every vote cast in the state.
- Tipping point
- Order the states the winner carried from widest margin to narrowest and add up their electoral votes; the tipping point is the state where the running total first reaches a majority. Its margin here is over the next-best candidate in that state.
- Narrowest path
- Of every set of states the winner carried, the one that would have given the runner-up at least 270 electoral votes with the smallest combined margin. Found by an exact search, not by taking the closest states in order. A tie or any result short of 270 does not count as a win.
- Switched voters
- One voter changing sides moves a margin by two, so a margin of N is overturned when more than N ÷ 2 voters switch. The minimum is the sum of that, state by state. Real elections never move this neatly; this is arithmetic, not a forecast.
- No majority
- When nobody reaches 270, including a tie, the House of Representatives chooses the president, one vote per state delegation.
The map is a toy: anything you flip on it is invented. Clicking a state hands its electoral votes to the next candidate on the 1980 ballot, then to the next, and finally back to the candidate who really carried it — nothing here changes what happened.
- Only the block of electoral votes a state cast for its own winner moves. District and faithless electors stay as cast, because individual electors — not the state — cast them.
- The majority line is 270, the threshold 1980 actually used, out of 538 electoral votes.
- If nobody reaches 270, the Twelfth Amendment sends the choice to the House of Representatives — which is how 1800 and 1824 really ended.
- The address bar carries your scenario, so a link you copy opens on the same map. Reset, or a link with no scenario, restores the real result.