With four weeks to go until Election Day, the 2024 polls continue to show a presidential race that remains on a knife’s edge — and well within the margin of error. That’s true for recent national polls like NPR/PBS/Marist, which found Vice President Kamala Harris with a narrow edge against former President Donald Trump — 2 points among likely voters, 50%-48%, within the poll’s margin of error (plus or minus 3.7 percentage points). It’s also true in the polls of the battleground states that will...