Mollie Cohen, a Ph.D. student at Vanderbilt, writes at AmericasBarometer about invalid voting in Peru and what that means for the upcoming presidential election. The upshot is that Peruvians do not trust political parties, so have the second highest (to Bolivia) rate of invalid voting, referring to intentional spoiling of ballots.
Since 1993, the number of invalid votes has been larger than the margin of victory between first and second place candidates in nearly 40% of all first‐round Latin American presidential elections. In other words, in more than a third of presidential elections, the second place candidate could have won the presidency had he or she captured these invalid votes.
Peru has a two round system so this is significant. The "I hate you all" vote could make the difference, but obviously chooses not to.
The most current Ipsos poll has Keiko Fujimori at 40.8% with no one else over 20%. She needs a majority to win in a first round. A major question is whether invalid votes in the first round remain so in the second. Do people spoil votes knowing the outcome will require a second election, then vote for real the second time? Or, do haters keep hating?