“It was the culmination of the party’s decision five years earlier to reject — by one caucus vote — the science of climate change…” – Alan Kohler, ABC News ABC

That off-hand line in Alan Kohler’s analysis of Sussan Ley’s post-election dilemma captures a truth bigger than the Coalition’s climate wars: again and again, the arc of history bends because one person changes (or casts) a single vote. From Canberra party rooms to the floor of the U.S. Senate, the “power of one” keeps reminding us that democracy is built on razor-thin arithmetic.

1. The one-vote pivot that rewired Australia’s climate politics

On 1 December 2009 Tony Abbott defeated Malcolm Turnbull for the Liberal leadership 42–41 – a solitary informal ballot stopped the count from an exact tie. Abbott immediately hard-lined the party against Kevin Rudd’s Carbon Pollution Reduction Scheme. That stance bled into the 2014 repeal of the Clean Energy Act and, as Kohler argues, seeded the Coalition’s wipe-out in 2025. ABCABC

Change one MP’s mind in that party-room spill and Australia’s last 16 years of climate policy – and perhaps three prime-ministerships – look different.

2. One son, one mother, 17 million new voters

Fast-forward to 18 August 1920. In Nashville, the Tennessee House split 48–48 on ratifying the U.S. Constitution’s 19th Amendment. Twenty-four-year-old legislator Harry T. Burn, wearing the anti-suffrage red rose, opened a letter from his mother: “Be a good boy and vote for suffrage.” He switched sides, broke the tie, and made Tennessee the 36th state to ratify – delivering American women the vote. Constitution Center

One filial nod changed the franchise for half the U.S. population.

3. One vote short of toppling a president

During Andrew Johnson’s impeachment trial in 1868, 35 senators voted to convict, 19 to acquit. Conviction needed two-thirds of the 54-seat chamber – one more guilty vote. Had just a single Republican dissenter gone the other way, Johnson would have been removed, the presidency re-shaped decades before Nixon or Clinton were even born. U.S. Senate

4. The annexation of Texas – 27 ayes, 25 nays

America’s map is larger today because in 1845 a joint resolution to annex the Republic of Texas squeaked through the U.S. Senate 27–25. If one pro-annexation senator had balked, Texas may have remained independent (or re-joined Mexico), the Mexican–American War might have played out differently, and the balance of slave and free states would have shifted. U.S. Senate

5. Myths matter too: Adolf Hitler and the “one-vote” legend

You’ll often read that a solitary ballot elevated Hitler to party leader. It didn’t. In 1921 he was actually elected 553–1; there was only one dissenting vote in a meeting of 554 members. The myth survives because the underlying moral is seductive. But accuracy is equally powerful – and a timely reminder to fact-check every “one-vote” yarn. Econlib

6. What these moments teach us today

1. 1. Every preference counts. Australia’s compulsory preferential voting can feel like busywork, yet the Kohler-Turnbull-Abbott saga shows how one caucus ballot – let alone one electorate preference flow – scales to decades-long consequences.
   2. Small chambers amplify stakes. Leadership spills, committees and state legislatures work in tight numbers; the smaller the room, the larger your individual leverage.
   3. Civic duty is compound interest. Harry Burn probably didn’t picture global women’s suffrage when he opened his mum’s letter. Your ballot, board vote or branch-stacking proxy may echo far beyond its immediate context.
   4. Fact-checking protects credibility. Repeating the Hitler myth dulls the force of genuine one-vote stories. Rigorous sourcing – whether in a blog post or a policy speech – keeps the lesson sharp.

7. A climate footnote with present-day stakes

Kohler’s piece argues that Sussan Ley now faces an existential choice: align with public demand for credible net-zero policy or cling to Nationals’ scepticism, and lose again. That decision may hinge on a handful of MPs – or even a single back-bencher in a Coalition party-room ballot. The next “one-vote” turning point could decide whether Australia stays a climate laggard or joins the leaders. ABC

8. Take-aways for the rest of us

• • • Vote – in every election, board meeting, union delegate race, or strata committee.
    • Engage – persuade one undecided friend; history says it might be enough.
    • Document – keep sources handy; someone will quote your example.
    • Stay humble – you rarely know in the moment which decision becomes the hinge.

Slow, deliberate participation – to borrow another favourite phrase – is smooth, and smooth is fast. The single ballot you cast today could ripple across generations. Don’t waste your shot.

References

• • Kohler, A. (2025, May 19). Sussan Ley’s choice: an electable climate policy or sticking with the Nationals. ABC News. ABC
  • ABC News. (2009, December 1). Shock win for Abbott in leadership vote. ABC
  • U.S. Senate. (n.d.). Impeachment Trial of President Andrew Johnson, 1868. U.S. Senate
  • U.S. Senate. (n.d.). Texas timeline: Senate votes to annex the Republic of Texas. U.S. Senate
  • Bomboy, S. (2023, August 18). The vote that led to the 19th Amendment. National Constitution Center. Constitution Center
  • Caplan, B. (2007, August 29). Fun history fact of the day. Econlib (debunking one-vote fallacies). Econlib