Kamala Harris and Tim Walz in Rochester, Pennsylvania, August 18, 2024. / CourtesyPhoto: REUTERS/Kevin Lamarque

(Reuters) -In the five weeks since U.S. President Joe Biden abandoned his flailing reelection bid, the Democratic Party's fortunes have changed dramatically, and this week the change will be on full display. 

Vice President Kamala Harris, now the party's candidate, is heading into the Democratic National Convention riding a historic whirlwind: her campaign has broken records for fundraising, packed arenas with supporters, and turned the polls in some battleground states in Democrats' favor.

Harris and her running mate, Minnesota Governor Tim Walz - have turned "joy" into a campaign buzzword, a pithy reminder of the despair the party felt just weeks ago. The two publicly accept their party's nomination at the convention in Chicago that starts Aug.19.

"This has been an historic transformation," said Joseph Foster, a 71-year-old former Democratic Party chairman in the Philadelphia suburbs who remains active in the party. "People are enthused, young people are engaged. I have never seen anything like it."

With less than 80 days to go to Election Day, the party is hoping to ride that wave of enthusiasm to victory.

That would make Harris, the first Black person and person of Asian descent to serve as vice president, the nation's first female president.

But pollsters and strategists from both major parties warn that the "sugar high" of Harris' initial surge will wear off, leaving simmering divisions among Democrats on issues like the economy and the Israel-Hamas war along with a fierce battle against Republican candidate Donald Trump.

Harris' historic personal story is "lovely and fine, but it's the issues that are going to ultimately decide this election. Those issues include inflation, security, leadership, and the world stage," Republican pollster Adam Geller predicted. 

Harris had her first major economy-focused speech on Aug.16 and laid out proposals to cut taxes for most Americans, ban "price gouging" by grocers, and boost affordable housing, an early nod to the party's progressive flank.

She will face increased public pressure to provide more details on policy in the upcoming weeks. Aides have signaled that she is unlikely to provide many specifics in some areas like energy to avoid alienating the moderate and progressive wings of her party.

Harris may also have to navigate intra-party squabbles over U.S. support for Israel's war against Hamas and familiar divisions between progressives and moderates on a host of policy questions such as energy, healthcare, and immigration.

About 200 social justice organizations plan to march at the Democratic National Convention on Monday to protest the Biden administration's continued support of Israel in a war that has killed more than 40,000 Palestinians in Gaza.

NEW MAP TO VICTORY 

Harris, who will address the convention on Aug.15, enters the week of festivities boosted by a string of polls that show she has already redrawn an electoral map that strongly favored Trump in the final weeks of Biden's candidacy.

Harris is leading or tied with Trump in six of seven swing states that are expected to decide the Nov. 5 election, according to the latest report issued from the nonpartisan Cook Political Report.

The election handicapper shifted its ratings for the swing states of Arizona, Georgia, and Nevada toward Harris after it had moved all three states to "lean Republican" in early July when Biden was still the Democratic candidate.

"I think what we have is a reset race where the Democratic candidate now has reenergized, or at least reconstituted, the Biden 2020 coalition, not completely, but it's much more put together than it was when Biden was on the top of the ticket," Amy Walter, Cook's editor, said in a call detailing the poll's findings.

Biden won the White House in 2020 with the strong backing of Black, Hispanic, and young American voters, but their enthusiasm for him this time around was sharply lower.

He finally stepped aside on July 21, under pressure from longtime allies and senior Democratic leaders amid growing concerns about his mental acuity and chances of beating Trump.   

Biden endorsed Harris and she quickly won the party's support. The change rapidly reframed the race, giving Democrats a boost and forcing Trump's campaign team to scramble in search of a new battle plan.  

A Monmouth University poll released on Aug. 14 found a substantial jump in enthusiasm among registered Democratic voters and a sizeable one among independents. 

In June, only 46 percent of registered Democrats said they were fired up about a Biden-Trump rematch -- that jumped to 85 percent in the latest Monmouth survey conducted earlier this month.

The jump in enthusiasm among independents went from 34 percent in June to 53 percent in the latest poll.

Still, Walter said concerns over immigration and the economy are helping Trump this time around after he lost his reelection bid against Biden in 2020. 

"It's a coin flip," she said of the race between Harris and Trump.