Presidential candidate and former vice president Joe Biden has taken the lead in the critical state of Pennsylvania.

With an estimated 95% of the Keystone State votes having been tabulated, Biden is closing in on collecting Pennsylvania, and thus, the presidency.

"What our decision desk is now doing," explained CNN's David Chalian, "is calculating what do we know about the outstanding vote in Pennsylvania, what do we know about the rate it's been coming in."

The bulk of the remaining ballots in Pennsylvania will come from Philadelphia and the surrounding areas, a segment that has overwhelmingly come in for Biden to this point.

"Look what just happened in Philadelphia," said Chalian, of Biden's continued success in the state's largest city.

"He got 87% of them. We know ... there's still a bunch of vote in Philadelphia to count.

When that kind of Biden advantage vote, gets put into the vote totals, it just boosts that level of confidence that this will be potentially out of reach for Donald Trump."

Currently, Biden maintains a 253-213 electoral vote lead over the President. As votes continue to trickle in from the Philadelphia area, the Keystone State's native son is inching closer to the White House.

"We need to see a level of confidence when we're looking for these calculations that the candidate in second place, now Donald Trump in Pennsylvania, is not at all likely to overtake the candidate in first place, now Joe Biden," Chalian added.

"When we get to that level of confidence... then a projection gets made."

The commonwealth of Pennsylvania carries 20 electoral votes, a bank that would get Biden past the coveted 270, the amount needed the clinch the presidency.

"We will await more vote to come into Pennsylvania, as we continue to make those calculations," Chalian reminded viewers.