In the US state of Pennsylvania, the Democratic Party's switch to Kamala Harris as its presumptive nominee for president has re-energized its campaign for the White House in a key battleground state, grassroots party activists say. "I believe we're going to have a blue landslide," said Bill Leiner, a volunteer with the Democratic presidential campaign in Allentown, a city of about 125,000 residents. "People are energized," he added.

In an unprecedented development in modern US electoral history, President Joe Biden on Sunday announced he was dropping his bid for reelection, and endorsed Vice President Harris's candidacy in the November poll. In Allentown, 70-year-old Leiner said he wasted little time in amending his existing Biden/Harris sign to show his support for the vice president. "The minute I heard Harris is going to be the person, I cut it off, and then kind of taped it up, and I got the first Harris sign in my town," he said.

Leiner, who works as a nurse, is "optimistic" about the Democratic Party's odds now that Harris is headlining the ticket. "It has to be Kamala Harris because if we don't pick Kamala Harris, we will lose," he said. Leiner believes Harris has the right tools to take on Republican Party nominee Donald Trump, especially in light of Biden's disastrous debate performance in June.

"She's going to carve him up," Leiner said. A few yards away, in his garden shed, dozens of signs from previous election and social awareness campaigns pile up. Unlike Leiner.