Etienne Tshisekedi was never keen to see his son succeed him, fearing that Felix lacked the ability and commitment to lead the party, but in March the party chose him as Etienne's successor.
And in November, he showed his true colours.
The current dictator, Joseph Kabila, had to leave power at least for a while, since the constitution allows presidents only two consecutive five-year terms.
He could legally come back after another five years, but in the meantime he had to find a presidential candidate who would do his bidding and keep his seat warm.
Eventually he chose an official candidate — an ally called Emmanuel Shadary — but the opposition parties thought they had a chance if they could unite behind a single candidate. The DRC's 84 million people are sick of living in a potentially rich country where most people are desperately poor even by central African standards.
So all the opposition parties got together in November to pick a single presidential candidate. Felix Tshisekedi was there, and he even agreed when the other opposition parties chose a different joint candidate for the presidency, Martin Fayulu.
But next day he broke with them and declared his own candidacy.
Was it just pique, or did he get a better offer? In retrospect, it was probably the latter.
The presidential elections were duly held at the end of December and, to everybody's astonishment, Tshisekedi won. The official candidate, Shadary, came last.
So why isn't everybody celebrating the triumphant return of democracy to the Democratic Republic of Congo?
Because nobody believes the numbers. Opinion polls before the vote gave Fayulu between 39 per cent and 43 per cent of the vote. Tshisekedi came a distant second with between 21 per cent and 25 per cent and official regime candidate Shadary got only 14 per cent to 17 per cent.
So Fayulu should have won — but he didn't.
Fayulu was leading Tshisekedi by almost two to one in the opinion polls. How and why did it come to pass that the official results gave Tshisekedi 38 per cent of the vote and Fayulu only 34 per cent?
Fayulu cried foul. The African Union said it had "serious doubts" about the result and announced that it was sending a delegation to the DRC.
And the influential Catholic Church of the DRC, which deployed 40,000 election observers, reported that the official results did not match its findings.
What probably happened is as follows. The outgoing president, Joseph Kabila, inherited his power from his father, a warlord called Laurent Kabila, when the latter was assassinated by his bodyguard in 2001. He also inherited the military commanders who brought his father to power, and held the real power in the regime. They, or their successors, still do.
There was never agreement among these commanders about whether Joseph Kabila was the right front-man for the regime.
Those who wanted a change may well have chosen Shadary as the regime's new official candidate against Kabila's wishes. Or maybe Kabila realised that Shadary wasn't going to win even with a lot of help from the people counting the ballots.
It appears that Kabila seduced Felix Tshisekedi with the promise of the presidency, and made sure the voting results came out in his favour. It was a stroke of political genius, because it makes it look like the opposition won. It didn't.
As soon as Tshisekedi's victory was "confirmed", he declared: "I pay tribute to President Joseph Kabila. Today we should no longer see him as an adversary, but, rather, a partner in democratic change in our country."
And almost everybody outside the DRC is sorrowfully going along with this shabby betrayal.
The African Union has postponed its delegation to the DRC indefinitely, and two respected African leaders, Kenya's President Uhuru Kenyatta and South Africa President Cyril Ramaphosa, have sent Tshisekedi their congratulations.
The southern African regional group SADC has also welcomed Tshisekedi's "victory", and urged all Congolese to support the president-elect in his bid to maintain "unity, peace and stability".
They are afraid that public protests over the rigged election would be met with massive violence, and risk tumbling the DRC into another catastrophic civil war.
At least this will be the country's first non-violent transfer of power, so the rest of Africa is telling the Congolese to swallow their pride and bide their time.
Half a loaf is better than none.
Gwynne Dyer's new book is Growing Pains: The Future of Democracy (and Work)
