The Brazilian election is just three days away and Dilma Rousseff’s lead is slipping.

The Workers’ Party candidate had as much as 51 percent of the vote in several polls but has slipped in some to 46 percent, as I point out in this short piece for the Christian Science Monitor World blog.

But what was most interesting to me was to see this note I got today from Alberto Almeida of the Analise Institute in São Paulo. Almeida said that many illiterate voters make a mistake and end up spoiling their electronic votes and so the estimates regularly overestimate the final tallies.

The presidential selection is the last of the six voters have to make (after governor, two senators, federal and state deputies), further complicating matters.

Lula’s vote was estimated at 3 points more than what he eventually got in winning in 2002 and 4 points more than in 2006, Almeida pointed out.

“The election will go to a second round,” he said.

It won’t make much of a difference in the grand scheme of things. Dilma will still win comfortably.

But it’s good news for democracy. And for campaign staff, pundits and journalists like me, who get four more weeks of work.