New Delhi, Aug. 1 -- HARARE - The opposition demonstrators who tried to gather in Harare on Friday did not get far. Police moved before the marches could form, threatening those who had planned to turn out and in some cases using physical force to disperse them, according to Human Rights Watch. By midmorning, the streets were quiet, not because people had lost interest in protesting, but because they had been stopped from doing so.

The immediate target of their anger was a constitutional amendment that passed Zimbabwe's parliament in June with almost no resistance from within the legislature. The law eliminates the right of ordinary Zimbabweans to directly elect their president. Under the new arrangement, parliament will make that choice...