The cacophony of bullhorns, fireworks and frenzied cross-country barnstorming in trucks, busses and three-wheeled "tuk-tuks" emblazoned with candidates' posters has come to an end, and a historic moment has arrived: tens of millions of Egyptians are heading to the polls today in the first democratic presidential election in the country's history, an election borne out of the 2011 revolution that ousted former President Hosni Mubarak and injected Egyptians with a novel feeling of excitement for participatory democracy. The campaign witnessed many firsts for long-alienated Egyptians, including the participation of the powerful Muslim Brotherhood and a televised debate between two of the front-runners that drew the kind of huge, captivated audience normally reserved for soccer matches between Egypt's two favorite teams, Al-Ahly and Al-Zamalek.

Given its status as the most populous and, arguably, most influential Arab state, the stakes are enormous both for Egypt's 83 million inhabitants and for relations with Israel, its Arab neighbors, and the United States. A host of critical challenges will await the next president, chief among them reviving the economy, creating jobs, ensuring internal security, and restoring trust and confidence in governmental institutions.

Curiously, though, the next leader will have to start this process not knowing what powers the presidency actually has in relation to the parliament or the armed forces. The old constitution, under which the president could declare a state of emergency, dismiss the parliament, and name key cabinet members , was annulled last year by the ruling Supreme Council of the Armed Forces (SCAF), and in the backward order of events scheduled by the SCAF, the date for presidential elections was set before the final writing of a new constitution. Further confusing the picture, the drafting of the charter has bogged down in disagreements over who should be appointed to sit on the drafting committee, while the ruling generals have threatened to issue a kind of temporary, interim constitution, which would give the new president sweeping powers and preserve the extensive privileges of the military.

Such a gambit by the SCAF could very well backfire, however, and push Egyptians back onto the streets to protest a renewed power grab by one of the two leading "felool" candidates, the so-called "remnants" of the ancien regime of Mubarak, Ahmed Shafiq and Amr Moussa.

Shafiq is a former Chief of the Air Force, Minister of Aviation and Mubarak's last Prime Minister, and Moussa is the 76-year old former Foreign Minister and previous Secretary General of the Arab League.

In contrast, the other two leading candidates are both Islamists. Abdel Moneim Abul Futouh is a relatively moderate Islamist who was expelled from the Muslim Brotherhood (MB) for defying their authority and unilaterally declaring his candidacy. Mohamed Mursi is the Brotherhood's official candidate, awarded that honor after their more popular initial choice, Khaled Al-Shater, was disqualified by the Elections Commission for having an arrest record. Moreover, Islamists from the Muslim Brotherhood and the more hard-line Salafist groups won more than 70 percent of the seats in the lower house of Parliament, and enjoy widespread support among the generally devout populace.

Should one of the "felool" -- particularly Shafiq -- ultimately prevail and then be handed Mubarak-like powers by the SCAF, the reaction from the well-organized Islamist opposition (and less-well organized secular youth and activists) will no doubt be swift and fierce. Already, the Islamists in the parliament on Monday forced the generals to back down on their intention to issue constitutional amendments outlining the presidential powers before the first round of the election. That contentious discussion between the SCAF and party leaders will now be resumed after the vote.

At this point, however, it is anybody's guess as to who will take the prize. Various polls have revealed divergent results, and much will depend on how successful the Muslim Brotherhood is at turning out the vote of their members for Mursi, perhaps the least charismatic of the four main contenders. Abul-Futouh, a more moderate Islamist than Mursi, has the support of some secularists, independents and the hard-line Salafis, while Moussa is the most widely-recognized of the four and is well-remembered for being highly critical of Israel as Foreign Minister. Shafiq can expect the votes of army vets and their sympathizers, as well as the many Egyptians who yearn for a return of order and stability to the streets of their cities. If no candidate receives an outright majority from the voting today and tomorrow, Egyptians will once more line up to vote June 16-17 in a run-off election between the top two vote-getters in the first round.

The open question of what authority the new president will have should not derail Egyptians from casting their ballots, though, as some boycott enthusiasts advocate. The problems facing the country -- the staggering unemployment among the young, a fragile economy, lawlessness in the streets, and a sclerotic bureaucracy, to name a few -- need to be addressed quickly by whoever takes his seat in the president's Ittihadiya Palace. After 16 months of frustrating mismanagement of the transition, the ruling generals have pledged to turn over executive power at the end of June. Assuming the elections this week and in June are conducted freely and fairly (international and local monitors and party representatives should help prevent fraud), one would hope that all Egyptians, no matter how disappointed they are in the outcome, accept the result and engage in peaceful politics in order to shape their future course. To be sure, the road to a fully democratic and prospering Egypt will be a long and bumpy one. But remembering where Egypt stood a year and a half ago, today's vote must be considered a very positive step along the way.