CAIRO (AP) — Former military chief Abdel-Fattah el-Sissi, if he wins Egypt's presidency as is widely expected, will have an overwhelming presence over a shattered political scene. Egypt's once dominant political force, the Muslim Brotherhood, is crushed under a relentless crackdown. Non-Islamist parties are weak and largely acquiescent to his power.

But the political vacuum is hardly a stable one.

Supporters of the ousted Islamist President Mohammed Morsi vowed Thursday to push ahead with their campaign of protests against what they called el-Sissi's "republic of fear," betting that over time the public will turn against el-Sissi if he fails to address the monumental challenges facing the country, including a crippled economy. Secular anti-military youth movements — who also oppose the Islamists — are also watching whether public opinion turns.

Amid that vacuum and in the absence of his own party, el-Sissi surrounded himself with politicians, technocrats and big businessmen from the era of ousted President Hosni Mubarak and has the powerful backing of the military and the security forces. That has deepened concerns his presidency would mean a return of the autocratic methods of the past that prompted the 2011 uprising against Mubarak.

El-Sissi, who as military chief removed Morsi from office in July and has since been the most powerful figure in the country, announced Wednesday that he had resigned from the military and will run for president in elections expected next month. The election committee is expected over the weekend to announce the date of the election and open the door for formal candidacies.

So far, only one person has announced his intention to run against el-Sissi — Hamdeen Sabahi, a leftist politician who finished third in the 2012 presidential election. Other prominent figures, including Islamists who broke away from the Brotherhood, have publicly said they won't compete, given that el-Sissi is widely assumed to be the sure victor.

Islamist supporters of the Brotherhood and its allies, which dominated elections since Mubarak's 2011 fall, are likely to stay away from the polls.

El-Sissi's campaign will be an unusual one, given fears of threats to his life amid Egypt's sharp polarization and the campaign of attacks by Islamic militants in retaliation for Morsi's ouster. In his announcement Wednesday, he acknowledged he won't run "a traditional campaign."

El-Sissi will not appear in street rallies but will base his campaign on TV appearances, said Abdullah el-Sinnawi, a veteran journalist close to the former military chief. El-Sissi has taken on a private security firm for the campaign but plainclothes troops will also be heavily involved in his appearances, military officials told The Associated Press, speaking on condition of anonymity because they were not authorized to talk to the press.

There has been a wild media fervor surrounding el-Sissi for months, touting him as the nation's savior and the sole figure strong enough to rule — making weighing his true popularity difficult. But large sectors of the population are likely to back him out of a desire for stability or out of resentment of the Brotherhood. The leader of the ultraconservative Islamist al-Nour Party, Younis Makhyoun, said el-Sissi has wide popularity in rural areas, where most of Egypt's population of 90 million live.

In the fractured political landscape, el-Sissi has put together a political machine centered on himself that may give hints into the nature of his presidency.

The military publicly committed itself to el-Sissi's presidency when its top body of generals, the Supreme Council of the Armed Forces, announced its support for his candidacy earlier this year. Its branches are lined up to help el-Sissi even after he took off his uniform.

The military's Morale Affairs department has a strong influence with Egypt's privately owned media. It meets regularly with the managers of the country's main biggest TV stations, which are owned by prominent businessmen who have strong ties with the military or are ferociously anti-Islamist.

Morale Affairs and military intelligence conduct frequent public opinion polls, which are not released, but which are fed to el-Sissi, several military officials told The Associated Press. Several polls, for example, measured public opinion on the crackdown on Islamists, and the officials said one showed strong public opposition to any reconciliation with the Brotherhood — though the officials released no information on the polls and it was impossible to know their content. The officials spoke on condition of anonymity because they were not authorized to talk to the press.

El-Sissi took steps to secure his position during his last weeks in the military.

In one of his last public acts in uniform this week, el-Sissi inspected a new Rapid Reaction Force, which officials described as an elite unit to be deployed for threats to national security and to combat terrorism — a term used in reference to riots and protests by the Brotherhood.

El-Sissi orchestrated a reshuffling of the military's top officers to put close associates in key posts. In changes announced the past few days, his former chief of staff Sedki Sobhi, a lieutenant general, was promoted to full general and named defense minister and head of the military.

After long negotiations, former military intelligence chief Mahmoud Hegazy — whose daughter is married to one of el-Sissi's sons — was named the new chief of staff, passing over the head of the air force who had widely been seen as the likely successor to the post.

On the civilian side, his campaign organization already includes figures prominent from the eras of Mubarak and previous presidents. Among them are Amr Moussa — a former Arab League chief and foreign minister who ran for president in 2012 — and veteran journalist Mohammed Hassanein Haikal, a political insider who was once an aid to iconic leader Gamal Abdel-Nasser in the 1950s and 1960s.

Also backing him are an array of political groupings and liberal parties, some created after the fall of Mubarak in 2011, others arising since Morsi's ouster, set up by leading figures from Mubarak's former ruling party or former top officers from the security agencies.

Notably, he is not a member of a political party. Under Mubarak, the ruling National Democratic Party was a key tool for his rule, running all levers of government and society — with the help of the security agencies. So far el-Sissi has shown no sign of repeating that — though that could change. El-Sinnawi said he will likely work through existing parties, but suggested that if those prove too disorganized, el-Sissi could seek backing of independents who would exploit parties' weakness and sweep the vote in parliamentary elections.

In comments to fellow officers before Morsi's ouster that were later leaked to the press, el-Sissi acknowledged that the state had been "dismantled" after the 2011 uprising and "now its structure is being rearrangement" — a recognition that the old status quo is gone and old rules no longer apply.

One key question early on will be whether el-Sissi uses his political strength to seek some form of reconciliation with the Brotherhood and its Islamist allies that would ease their protests and find some way to include them in the political process.

A move for reconciliation would be a dramatic one, since neither side has shown any readiness for it. The military-backed interim government has waged a relentless crackdown on the Brotherhood and other Islamists. Security forces have killed hundreds as they crush pro-Morsi protests, and around 16,000 people have been arrested, including most of the Brotherhood's leadership.

At the same time, Islamic militants have stepped up attacks on police and the military, killing dozens in bombings and shootings and stoking a fear of terrorism among the public. Authorities have blamed the Brotherhood for orchestrating the violence, a claim the group denies.

The Brotherhood, in turn, has refused to recognize the post-Morsi system, depicting his ouster as a coup by the military to crush democracy.

On Thursday, the Brotherhood-led coalition of Islamist groups called for a massive rally on Friday against el-Sissi, saying "his hands are stained with the blood of thousands of Egypt's best sons."

After el-Sissi's announcement Wednesday that he will run, it said in a statement, "it is clear to all that Egypt has fallen under a bloody terrorist coup whose agenda is create a republic of fear, oppression and poverty."

With little known about el-Sissi as a politician, there are two possible paths he could take as president — one would be to try to repair the political system in a more democratic way, the other would be to fall back on the old autocratic rule.

"He has popular support through which he can take drastic decisions and move forward, but on the other hand this could pave the way for a new military fascism that will block the path of democratic transition," said prominent political scientist Hassan Nafaa.