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?

The new Quinnipiac University poll shows Harris leading Trump in the swing states of Pennsylvania and Michigan, which are both seen as critical states for the two frontrunners. The poll comes as both campaigns court voters in swing states less than 50 days out for November’s election.

The International Brotherhood of Teamsters declined to endorse a presidential candidate on Wednesday after releasing internal polling that showed a majority of its members supported former President Donald Trump.

In a series of new polls conducted by USA TODAY and Suffolk University, Pennsylvania appears to be turning hard toward the Democratic nominee, who leads Trump — not only in the state but in two of Pennsylvania’s key counties, according to three exclusive polls taken after last week’s debate.

A new poll of Pennsylvania shows Vice President Kamala Harris and former President Donald Trump remain locked in a close presidential race, while Dave McCormick is gaining ground against Bob Casey

Donald Trump and Kamala Harris are working overtime to secure wins in the key battleground states. Here is a closer look at how the candidates are polling this week.