Sudan's Omar Bashir fended off a march by opponents on his presidential palace in the capital, Khartoum, unleashing his security forces in hopes of putting an end to an Arab Spring-style uprising. But nearly a week of protests has pointed to the weaknesses threatening his 29-year hold on power.Despite the heavy hand of police, who have reportedly killed at least 37 protesters, Bashir's response has been feeble. He left the capital ahead of Tuesday's march on his palace, and he has been fumbling and vague in addressing the economic crisis that prompted the outburst of anger.Perhaps most alarming for Bashir, an Islamist who came to power in a 1989 military coup, the powerful military and security agencies have only voiced half-hearted support for him amid the turmoil.On the streets, the lengthy battles with police on Tuesday in Khartoum may have only emboldened Sudanese to take on the security forces again."Today, we the Sudanese people ... have crossed the point of no return on the path of change," a coalition of professional unions that organised Tuesday's march said in a statement afterward. "We will pursue all options of peaceful, popular actions ... until we bring down the regime that continues to shed blood. Today, more than any time before, we are confident in our collective ability to realise that."Bashir, who is in his mid-70s, put down two previous bouts of protests and may do so yet again. But the rule of one of the longest serving leaders in the Middle East is clearly fraying.Bashir's Leadership The Sudanese leader has held onto power despite a series of major setbacks over the past decade. The first was in 2010 when he was indicted by the International Criminal Court on charges of committing crimes against humanity and genocide in the Darfur region.He managed to build outside ties that prevented his complete isolation but has been weighed down by the stigma.More damaging was the 2011 secession from Sudan by the mainly animist and Christian south. The split, approved in a referendum by southerners, came under a peace deal signed by Bashir that ended a draining, decades-long civil war. But as it became independent, the south took with it three quarters of Sudan's oil wealth.The north's economy has struggled ever since. In recent months, Bashir devalued the currency, causing a spike in prices and worsening the hardships faced by most Sudanese. The public already is wrestling with fuel shortages, and a decree to raise the price of bread proved to be spark that set off the latest protests.Bashir has done little to help himself. He headed to a region south of the capital ahead of Tuesday's march on his palace. It was a previously scheduled trip but was widely interpreted as fright. There, he tried to put on a show of strength, but his speech at an outdoor rally attended by several hundred people was lackluster, relying on quotes from the Quran vowing that God will provide for people.He promised economic reforms but gave no details. He blamed the crisis on unnamed enemies of Sudan and called the protesters traitors, mercenaries, agents and heretics. Afterward, he stayed on the makeshift stage and performed his trademark dance to local music while waving his cane.Domestic SupportBashir still dominates Sudan's political class. Loyal lawmakers are rallying support for constitutional amendments that would allow him to run in the 2020 elections.But his real power base is the military, which has dominated Sudan since independence in 1956. Its support for him in the unrest has been less than resounding.In a statement on Sunday, several days into the protests, the military said it stood behind the country's leadership but didn't mention Bashir by name. Instead, it talked of preserving the nation's security and "achievements."Later in the week, the leader of a powerful paramilitary force who reports directly to Bashir delivered thinly-veiled criticism of his rule. Lt General Mohammed Hamad Daqlou of the Rapid Support Force called on the government to "secure services, fulfill its duties and create the means for a dignified life" for Sudan's people.He said a "realistic and radical solution" must be found for Sudan's economic crisis, and he called for "corrupt individuals who sabotage the economy" to be brought to account.Regional AlliesAnother possible judgment on Bashir was the silence of his Arab allies.Only the Gulf nations of Bahrain and Qatar publicly stated their support for Bashir. No word came from his most important backers, Saudi Arabia and the United Arab Emirates. The two countries have long given financial support to Khartoum, and Bashir sought to strengthen ties even further by sending Sudanese troops to Yemen to fight alongside them against Iran-aligned rebels there.Their silence suggests what an unreliable ally they consider Bashir to be. The Sudanese president has at various points forged close ties with the Saudis' and Emiratis' top regional rivals - Iran, Turkey and Qatar - apparently trying to play the sides against each other to extract more from them.Sudan's neighbour to the north, Egypt, has also refrained from voicing support for Bashir. Egyptian President Abdel-Fattah al-Sisi has courted Bashir for years, hoping to secure his goodwill in Egypt's dispute with Ethiopia over that country's construction of a massive dam that Egypt fears will reduce its share of the Nile River.But the mercurial Bashir has moved closer to Ethiopia and stoked a long-running border dispute with Egypt.Western countries have largely shunned Bashir since the ICC charges but they remain key donors of aid to Sudan. The United States, Canada, Norway and Britain have demanded Khartoum investigate "credible reports" that Sudanese security forces used live ammunition against protesters.In a joint statement, they referred to the constitutional right of the Sudanese to peaceful protests and labelled their demands as "legitimate."* Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and Facebook.