In sport, as the Rugby World Cup reminded us, it's often the team more focused, united and ruthless on the day who come out on top.
The other side may be more favoured, have higher levels of talent and skill, and a more consistent record.
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But they can still be battered against an unyielding defensive wall raised by opponents who buy into a common strategy and execute it without hesitation.
In the case of the US impeachment inquiry against US President Donald Trump, two very different approaches are in play, and it is still uncertain which has been more effective in shaping public opinion and which will work the best heading into the 2020 election year.
There's a marked difference between attitudes in the wider public arena and among Trump's core support. But the party data helps shore up political backing for the President among elected Republican officials.
For instance, a YouGov poll showed Americans believed by 46 to 38 per cent that Trump should be impeached and by 46 to 40 per cent removed from office. But in Trump's own party, 81 per cent of Republicans were against impeachment and 83 per cent against removal.
Gallup estimated in early November that 30 per cent of Americans identify as Republican, 31 per cent as Democrats and 38 per cent as Independents.
YouGov found that 58 per cent of registered voters believed Trump asked a foreign leader to investigate a political opponent, while 51 per cent thought he withheld military aid to Ukraine and abused his power.
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A CNN poll found a marked gender gap on impeachment, with 61 per cent of women and 40 per cent of men in favour.
With Democrats in charge of the US House of Representatives, a full House impeachment vote could bring an unwelcome Christmas present for Trump. But there has been no crack in the Republican wall. Any subsequent trial in the Republican-controlled Senate aimed at removing him looks doomed to fail.
After the hearings, Republican congressman Will Hurd called Trump's actions "inappropriate" but short of impeachable. "I have not heard evidence proving the President committed bribery or extortion," he said.
The testimony of Russia expert Dr Fiona Hill focused attention on how the scandal reflects ubiquitous problems – conspiracy theories, fake claims and extreme political tribalism. Americans are struggling to agree on objective reality. "Truth is questioned," she said.
CNN analyst Ronald Brownstein noted: "The biggest lesson ... maybe that no House Republican was ever gettable, that there was no level of evidence that would cause them to challenge a president of their own party who is expressing the priorities and resentment of their base."
New Yorker writer Susan Glasser said there was "one unequivocal result: A Republican stonewall so complete, it cannot and will not be breached".
She added that the Republican defence, "in essence, is that facts are irrelevant, no matter how damning or inconvenient, and that Trump has the power to do whatever he wants, even if it seems inappropriate, improper, or simply wrong".
The Democrats are taking the game to their opponents, but Republicans are determined to protect their leader and their hold on power.