CAIRO -- A campaign play for the votes of Egypt’s taxi drivers by presidential candidate Ahmed Shafik says much about the final days of this country’s first democratic presidential election.

“Did you hear Shafik’s announcement? He is going to win the taxi vote. You must endorse us now,” a member of the Muslim Brotherhood told Ahmed Maher, a leading figure in last year’s demonstrations that toppled Hosni Mubarak, according to Maher. “We must meet right away.”

At the hastily arranged meeting, Brotherhood representatives promised to meet the demands of Maher and other revolutionary figures for in exchange for their endorsement of Mohammed Morsi, the Brotherhood candidate running against Shafik, Maher said. But when he asked for specifics, the negotiations collapsed in what has become the an intractable problem for the Brotherhood: It still has not won the endorsement of their candidate from largely secular revolutionaries, even though they loathe the idea that Shafik, Mubarak’s last prime minister, could win.

The back and forth negotiations have come to define the period between last month’s first round balloting and this week’s run off. Political parties have called their followers into the streets in hopes of recreating the sense of unity that led to the fall of the Mubarak regime. But the elections and the taste of political power has made it difficult, if not impossible, for the parties to unite enough to ensure that a Mubarak holdover doesn’t retake the presidency, this time in a democratic election spurred by their movement.

The disparate revolutionary groups cannot agree on who speaks for them and what they want. And the Brotherhood cannot agree on what they need to do to win the revolutionary vote. Both sides can’t even agree on how important the taxi driver vote is.

But they do agree that the fate of the revolution rests with the Brotherhood.

“It is really on us to prove to people that we are up to the responsibility and willing to work with others,” said Amr Darrag, a Muslim Brotherhood representative in Giza.

The runoff, which features two days of voting that begin Saturday, should easily go to the Brotherhood. The Brotherhood’s Morsi and the candidates identified as revolutionary garnered 65 percent of the vote in last month’s voting, when there were 13 contenders. Candidates with ties to the Mubarak regime – Shafik and former foreign minister Amr Moussa -- earned 35 percent. In the two-man runoff, that would seem to give Morsi, who came in first in the initial balloting, a huge edge over Shafik, who finished second.

But Hamdeen Sabahi, a secular Arab nationalist and socialist, and a revolutionary favorite, has refused to endorse Morsi, and his bloc of supporters could be key to the outcome: Sabahi won the first round in nearly every major city, including Cairo, the capital, and Alexandria, the country’s second largest city.

“Those who are endorsing Morsi are doing so because they believe this is a revolutionary decision. And after that they can change Morsi,” Ayman el Sayad, political analyst and editor in chief of a magazine, Weghat Nazar. “If Shafik wins, that means the revolution was wrong. It will not end the revolution but it will break the spirit of a lot of youth.”

On the streets of Cairo, there is increased talk of boycotting the vote all together from those who consider the race as one between the two best-organized political factions in Egypt – the regime vs. the Brotherhood -- and not a true expression of last year’s revolt.