Analyst Mark Halperin said early voting numbers need to be tracked "day to day" and these figures are "more important than the polls right now" because "it's giving us insight into a variety of factors that are counting for a Republican overperformance by various metrics in the early voting in the battleground states". But one downside of relying too much on these early voting numbers id that it's not know who they are voting. "It can change. We don't know exactly who's casting these ballots, how they are voting etc," Halperin said.