I am not sure if there is anything called "battered man syndrome."
The following might be viewed by some as a simplistic view about the 50% Zimbabweans who voted for Mugabe, but it is an attempt to unpack the issue. The following five reasons are some of the reasons that I believe might explain this strange phenomenon.
1. The History of Liberation Struggle of the 1970s
Mugabe led a very brutal war against the Smith government in the 1970s. This was a guerrilla war which also involved the population (especially in the rural areas). The ZANLA (ZANU's military wing) would penetrate into Zimbabwe from their bases in Mozambique and engage in battles with the Rhodesian army. The ZANLA forces depended on the people in the rural areas for support, information about the movements of the Rhodesian soldiers in the area, food and clothing. The people were part and parcel of the war. The ZANLA forces would also hold rallies and political meetings with villagers at night to "politically educate" them, and also to ensure their support. Who ever did not support the war or was accused of having informed the Rhodesian soldiers about the movements of the ZANLA forces, was considered a "sell-out" and would be killed in full view of the others. And in some cases the entire immediate family of the "sell out" would be killed (including children) in public. This was meant to send a message to the people that "if you do not support us you die." The liberation war was often driven on fear, "just and necessary" as some people might argue it was (in order to liberate people from the oppressive white regime).
Of course in such a war, there are also innocent casualties, people who are falsely accused and killed.
Any Zimbabwean who is about 42 years old and older still has vivid memories of this war. More than 28 years after the end of the war, some people might expect these people to have lost the memory and fear of the war, but the stories of people who experienced World War 2 in Europe, who are still traumatized by it almost 60 years later proves that some memories last forever. One notices that this older generation of Zimbabwean voters has been the power base of ZANU-PF over the years. Without generalising too much, many of these would rather vote ZANU-PF if that would stop the return of some form of violence. The violence perpetrated by the so called "War Veterans" in the early 2000s and now just before the June 27 re-run election, proved that ZANU-PF is still a militant party which easily resorts to violence to achieve its goals and therefore unable or unwilling to allow the democratic will of the people prevail, if that will threatens its power. The War Veterans of the 2000s called their violent actions the "Chimurenga" i.e. the liberation war.
All through his 28year rule, Robert Mugabe has constantly referred to the war of the 70s and at every opportunity reminded people that his party is going to war to fight the "puppets of the West" (that's what he calls any opposition party). The militant nature of the propaganda churned by the State media (100% controlled by the government/ZANU-PF) has always reminded people that for ZANU-PF "the bullet is more powerful than the X on the ballot paper."
2. The ZANU-PF Grip on the Rural Population
The apposition parties have always been strong in the urban areas where the effects of the economic collapse are immediately felt as jobs are lost, food and rental prices go up etc. But ZANU-PF, because of their experience in the war of the 70s where they heavily relied on the rural population, realised that they need to close out the rural areas from the opposition. The majority of the Zimbabwe population (maybe 60%) is in the rural areas. Chiefs and Heads of Villages are the authority figures in the villages. They allocate land to people and they are a force to reckon with. Right from the start, Mugabe made sure the Chiefs were on his side. This is achieved either through bribery or intimidation. He gave them certain powers and benefits but on condition that they towed the government/ZANU-PF line. That way, the chiefs "campaigned" for Robert Mugabe. Villagers have always been made to understand that there was no room for opposition people in the areas. In the 2000, Mugabe gave Chiefs cars, tractors, salaries etc. At meetings where these benefits were announced, government ministers or Mugabe himself would publicly announce that if a Chief was found to be an opposition supporter he would be stripped of his Chieftainship and benefits taken away. Chiefs were also told to ensure that their people voted "correctly" i.e. vote for ZANU-PF. There have been elections where villagers were told to go to polling stations in groups to vote. There have been cases where ZANU-PF had told villagers that, government would know whether the majority in the village voted ZANU-PF or another party. This was of course easy to know because in most cases there was one or two polling stations in each village and people voted at specific polling stations where they were registered on the voters roll. It would be easy to know that the majority in the village voted ZANU-PF or another party (without knowing who voted for who specifically). ZANU-PF threatened to stop any aid and development in villages which voted for any other party. In the urban areas, it was a different story because people were more "independent" from such threats and did not depend on "aid" from government to the same extent as the rural areas. On top of that, there are no "Chiefs" in the towns and cities to enforce ZANU-PF's wishes.
But one should also not ignore the fact that Robert Mugabe did a lot of good things to uplift the rural areas which had been neglected by the previous white government. He put roads, clinics, schools and the people were very grateful. Such basic things normally mean the world to rural people, who then often remain indebted to the government forever. ZANU-PF then used this to campaign to the rural people, as if it was ZANU-PF as a party which did all that. These developments were mostly paid for through aid money from the western world, but the people never got that part of the story. They were told that ZANU-PF was building them roads and clinics.
3. Mugabe's Stronghold on the MediaThe Mugabe government has always had a tight grip on the media, both print and electronic media. The daily newspapers are state owned and state run. The government has absolute control on what gets published and how it is published.
Independent papers have struggled in Zimbabwe and many have closed down. In the 1990s, as the opposition became stronger a daily paper called "The Daily News" came up. It became so popular that it outsold the government papers e.g. The Herald and The Chronicle. The then Information Minister (Jonathan Moyo) crafted a media law which in the end led to the collapse of this paper. The printing press of The Daily News was bombed one night (a few days after Moyo had threatened it). Although the security people at the printing house reported to the police, the car which came with the "bombers" (and even its registration plates) to the police, a case was never opened (even today, 6 years later). The electronic media (TV and Radio) are also 100% state controlled. The propaganda from the media is nauseating. The opposition has little or no access at all. Opposition election adverts are rejected and not run and there is nothing anybody can do about it.
Radio, which has a wide coverage and the only source of information for over 90% of the population (especially rural people) is a ZANU-PF tool to indoctrinate, threaten and brain wash people. Unless people have an alternative source of information, all they hear and see and read is ZANU-PF propaganda.
Of late ZANU-PF has been "preaching" that the MDC opposition is a British puppet and that the economic miseries of Zimbabweans are caused by sanctions imposed upon Zimbabwe by the West at the request of MDC. The reason, people are told, is because the government took land from the whites to give to the blacks.
Blacks in Zimbabwe generally are farmers and the land issue was one of the reasons for the war of liberation. When ZANU-PF presents the story this way, many people who don't know otherwise (especially rural people who live from the land) believe it. ZANU-PF also tells people that if they vote MDC into power, MDC will allow the whites back and re-posses the land.
4. The Land Invasions in the 2000s
The land invasions of the 2000 reminded people that ZANU-PF is still militant at its core and will resort to violence to achieve its goals. This has reminded the older and rural people that even after 28 years of independence, ZANU-PF can go to "war". The land invasions were also used by ZANU-PF to bribe people. The issue of land was a legitimate one and many opposition parties in the past have always criticised the government of being too slow with land retribution. Robert Mugabe only did the invasions in the 2000 when he realised that the opposition was becoming popular and he needed something extra-ordinary to "regain" his grip on power. This is proven by the fact that many farms taken over in the invasions are lying idle or are unproductive (5 years later). If the purpose of the invasion was to start an agrarian reform which was equitable, then those farms would be productive today. The land issue was used to bribe people, create a hype around reversing the uneven land distribution as well as to punish the white farmers who were beginning to support MDC.
5. ZANU-PF's Huge Capacity to Bribe or Brutalise
ZANU-PF uses two methods to make sure people tow the line. They either bribe you (hence very little is done to solve the corruption. Corruption is part of the bribe) or they threaten you. In times of poor harvests, food aid has often been channelled through government agencies. People have often been threatened that if they don't support ZANU-PF, they won't get food. ZANU-PF membership cards have been asked for as proof before people get food aid. Those who are too stubborn to succumb to bribery have had their lives threatened and some have been killed or have their houses burnt down. Because the media is under government control and outside media is not allowed into Zimbabwe (without government permission but only few if at all ever get that permission), many of these stories are never reported to the outside world.
The five reasons above are only some of the issues that might help outsiders understand how the ZANU-PF machinery works and why they have managed to stay in power for so long in spite of their record of mismanagement and corruption. These are not exhaustive and might not explain the entire picture but they should go a long way in doing that.
Unless one actually lives in Zimbabwe and talks to people and hears their stories, one might wonder why things are the way they are and why one still finds a huge number (over 40%) of people voting for Robert Mugabe. Only an in-depth analysis will unpack all the complex reasons.
Finally, one must not forget to mention that there are also people in Zimbabwe who genuinely support ZANU-PF and Robert Mugabe and will die and kill for him. Why they support him, is for them to answer but the more difficult question would be "how many they really are?" My answer is, somwhere between 20 and 25%.