GEOFF BENNETT: The Democratic National# Committee announced today that Vice## President Kamala Harris has secured the# number of delegates in a virtual roll## call to win the party's nomination, which will# be made official after voting ends on Monday.

While on the campaign trail, the# vice president is trying some new## language on for size, like calling# her opponent Donald Trump weird.

Our White House correspondent,# Laura Barron-Lopez, has more.

LAURA BARRON-LOPEZ: On a fast-track campaign# for the White House, Vice President Harris is## trying something new, to call it as she sees it.

KAMALA HARRIS, Vice President of the United States# (D) and U.S. Presidential Candidate: He and his## running mate sure seem t.. (CHEERING) (APPLAUSE) KAMALA HARRIS: And, by the way, don't you find# some of their stuff to just be plain weird?

LAURA BARRON-LOPEZ: It's a notable change# from when President Biden was in the race.

JOE BIDEN, President of the United# States: Do you really want to go## back to the chaos of Donald Trump as pre..

AUDIENCE: No!

LAURA BARRON-LOPEZ: Much of his# language focused on Donald Trump## as an existential threat to the country.

JOE BIDEN: It's about your# freedom.

It's about democracy.

LAURA BARRON-LOPEZ: Now, campaign press# releases call Trump old and quite weird,## and Democrats across the board are# leaning into Harris' blunt approach,## from possible vice presidential picks# commenting on Trump's behavior... GOV.

TIM WALZ (D-MN): Have you ever seen the# guy laugh?

If he has laughed, it's at someone,## not with someone.

That is weird behavior.

LAURA BARRON-LOPEZ: ... to leaders of the party# addressing resurfaced clips of J.D.

Vance.

SEN. CHUCK SCHUMER (D-NY): Every day, Vance -- it# comes out Vance has done something more extreme,## more weird, more erratic.

LAURA BARRON-LOPEZ: Branding the# Republicans as creepy has caught on fast.

MAN: That's just the start.

LAURA BARRON-LOPEZ: In an ad released# by a PAC focused on young voters, .. conservative playbook Project 2025 is personified# as people desperate to control your personal life.

MAN: Your genitals are reserved for procreation.

MAN: If you freeze 12 eggs, you# should be required to have 12 babies.

MAN: Or else you're a serial killer.

And# I'm definitely not a serial killer.

Are you?

LAURA BARRON-LOPEZ: This shift in# language is a strategy that could## prove effective as Harris rushes to# define her opponent in a new way,## according to David Karp of# George Washington University.

DAVID KARPF, George Washington University:# The serious messagin.. that this is a threat to democracy if we take# him both seriously and literally this time,## that's important, but it's also a bummer.

And what we're seeing here is a way to talk# about this that is still on message.

It's still## on the theme.

But there's some joy, there's# some mirth, and there's some verve to it.

LAURA BARRON-LOPEZ: Since Democrats# have changed their tune rhetorically,## Republicans have tried to find a response.

Former presidential candidate Vivek Ramaswamy# said Democrats are being dumb and juvenile,## while Donald Trump tried to use Harris' words# against her in a recent interview with FOX News.

DONALD TRUMP, Former President of the United#States (R) ... Look at her past.

LAURA BARRON-LOPEZ: But for Republican strategist# Joshua.. state of Pennsylvania, Donald Trump should# stay focused on attacking Harris' record.

JOSHUA NOVOTNEY, Republican Strategist: Stay# off the personal stuff and talk about how## she mismanaged the border crisis, talk# about the inflation and the economy.

I## don't think anyone is sitting there# saying we enjoy paying twice as much## for our groceries than we did a couple# years ago.

Those are winning issues here.

I would ignore the weird comments and all# of that.

I think that will backfire on## Democrats as being a little too mocking# and childish and kind of beneath them.

LAURA BARRON-LOPEZ: Donald Trump# is no stranger to name-calling,## recently saying Harris is dumb as a rock,# demonizing her on the campaign trail... DONALD TRUMP: She has no clue.

She's evil.

LAURA BARRON-LOPEZ: ... and even# mocking her biracial heritage.

DONALD TRUMP: She was Indian all the way,## and then all of a sudden she made a turn,# and she went.

She became a.. LAURA BARRON-LOPEZ: Trump's reactions are another# sign the weird attack is landing, Karpf said.

DAVID KARPF: Part of the reason we know# this is working well isn't just that## it's going viral online, but that it has# her opponents stuttering in response and## saying it's not fair.

When you have# your opponents reacting in ways that## amplify your message and make them# uncomfortable, you keep on doing that.

KAMALA HARRIS: When we fight, we win!

LAURA BARRON-LOPEZ: Michelle Obama's, "When they# go low, we go high," may no longer be Democrats'## North Star, but it's a choice that could end up# boosting Harris' self-described underdog campaign.

For the "PBS News Hour," I'm Laura Barron-Lopez.