With the presidency likely dependent on how Pennsylvania votes in this year's presidential race, many political polls are being taken in the Keystone State. But what explains the great difference in the poll results?

Given the recent polls and the collapse of the lead he once held over President Joe Biden, any path Donald Trump has to the White House must go through Pennsylvania — generally acknowledged as the most important swing state. Pennsylvania’s 19 electoral votes are the most among the seven top swing states.