So it's a moment to savour for the Conservatives in Newark.
Their candidate Robert Jenrick, an auction house director, hammered home 17,431 votes to win the seat… and in some style.
UKIP's Nigel Farage had promised a political earthquake in Newark.
Roger Helmer, his standard bearer in Newark, slashed the Tory majority. Sure, enough for a tremor but 7,000 votes short of causing real shock waves.
"Look, we've won a six-fold increase in our vote," Mr Helmer, a sitting East Midlands MEP, told me.
"It's Labour who should be worried. We've also served notice on any Conservative MP with a majority of less than 10,000. We are after you."
UKIP polled 10,028 in the by-election which works out as 26% of the vote. At the last general election, UKIP barely registered 4%.
It was Nigel Farage who talked of throwing the kitchen sink at causing an upset for the Tories in Newark.
The UKIP leader was in bullish form when he arrived at the count in the early hours.
Yet the lesson of this election is that it was David Cameron who threw a tactical kitchen sink at this contest. The Tory campaign was an object lesson in how to win tricky by-elections.
The PM's four visits to the constituency strengthened party morale on the ground, focusing the Tory campaign and showing his intent.
Frogmarching Conservative MPs to Newark for a touch of canvassing also underscored the Tory determination to retain the seat.
Their overall majority from the last general election may have been halved by UKIP but, on a 53% voter turnout, Robert Jenrick secured 44% of the popular vote.
Little wonder the prime minister was quick to tweet congratulations to his newest MP.
The party's last by-election victory when in power was a generation ago, when a youthful looking William Hague won Richmond.
There was by-election misery for the Lib Dems… again.
The party's David Watts finished with less than 3% of the vote and lost his £500 election deposit.
The party was in sixth place, behind David Kirwan of the Greens and independent candidate Paul Baggaley, a campaigner for Newark Hospital.
Mr Watts said ruefully: "At least I beat Bus-Pass Elvis."
That's a reference to Dave Bishop, who polled just 87 votes.
There was no repeat of the embarrassment when Bus-Pass Elvis beat the Lib Dems in a council by-election in Nottingham.
And there's little comfort for Labour. Michael Payne finished third with 6,842 votes, which is a 17% share, a 5% fall since 2010. That's not the place Labour needs to be with a year to the next general election.
By-elections can be unpredictable and not always a guide to future voting intentions.
But a party leader, especially one who's in Downing Street, always feels so much better when his party can win, regardless of any mid-term blues or protest votes.
It's good for giving some political breathing space and keeping trouble from the doorstep… at least for the time being.