POLITICS INTEL U.S. Voter Turnout Patterns and Electoral Margins Presidential election turnout has ranged from 49-62% of eligible voters over the past 40 years, yet shifts of just 2-3 percentage points in swing states have determined the last four elections. In 2020, Biden won Arizona by 0.3%, Georgia by 0.2%, and Pennsylvania by 1.2%—margins smaller than typical polling error. This pattern reflects a structural reality: roughly 40% of eligible Americans never vote, meaning elections are decided by turnout dynamics among a shrinking pool of persuadable voters in fewer than a dozen states. Why This Matters: Understanding voter participation baselines explains why both parties invest disproportionately in turnout operations rather than persuasion in most regions. When 80%+ of voters have already decided their preference, campaigns focus on mobilizing their base and the remaining 15-20% of true persuadables—meaning modern elections are increasingly about execution and demographic targeting rather than broad ideological debate.