The prime minister's critics will receive the message that other unpopular measures down the track - perhaps on public spending cuts - can also be defeated.
The first rule of U-turns, as a veteran former cabinet minister told me last week, is to do them quickly.
Liz Truss and Kwasi Kwarteng decided late last night to cut their losses, both saying this morning that the policy of abolishing the 45p rate for those earning more than £150,000 had become aDoing so in the glare of the spotlight at their party conference, on the day of the chancellor's keynote speech and meetings with business leaders, couldn't be a more high-profile backdrop, but confidence in the measure had been sapped.
As a senior minister who had supported the policy told me, it was a minor measure, worth around £2bn a year, which was not worth the criticism. It was crowding out the big-ticket items Truss has announced, including the £150bn two-year freeze in energy bills and the reversal of the National Insurance rise, which benefits ordinary families.'Was it your idea to cut top tax rate?'
Another minister in Truss's government told me bluntly yesterday,"45p isn't going to happen, we don't have the numbers". Truss's allies hope she's stemmed the damage and that votes on that National Insurance policy next week - in which many Tories who voted for the rise a year ago will be trooped through the lobbies to vote to axe it - will be a point of unity and a chance to reset after this debacle. After all, the next election is a long way off.