Voting with your feet.

An article on the website CFR.org reports that

Some sixty thousand Zimbabweans were deported from Botswana in 2006, and over 23,000 were deported between April and November 2007. South Africa deported over 150,000 Zimbabweans in the first nine months of 2007, according to Refugees International.

The report goes on to point out that

... the primary reason Zimbabweans leave their country: the need for money.

These people are economic refugees who are simply fleeing Zimbabwe's economic collapse. The huge number of such people just goes to show how bad the situation in Zimbabwe has become.

There is little point in trying to bring about change by voting in an election in Zimbabwe, so people vote with their feet ... repeatedly,

"These repatriations are more or less a vicious cycle," says Moses M. Gaealafswe, Botswana's chief immigration officer told CFR.org. "You arrest them today, you repatriate them tomorrow, next week they are here."