Republican presidential candidate Donald Trump will try to show swing voters that his likely new rival, Vice-President Kamala Harris, has her fingerprints all over two issues he is counting on for victory in November: immigration and the cost of living.

“Harris will be easier to beat than Joe Biden would have been,” Mr Trump told CNN shortly after Mr Biden’s announcement on Sunday.

Sources within the Trump campaign said it would cast Ms Harris, the likely Democratic candidate after President Joe Biden quit the race on Sunday, as the “co-pilot” of administration policies, which it says are behind both sources of voter discontent.

Mr Biden’s sudden exit and endorsement of Ms Harris upended the race just eight days after Mr Trump survived an assassination attempt at a campaign rally.

Sources told Reuters that Mr Trump’s campaign had for weeks been preparing for Ms Harris should Mr Biden drop out and she win her party’s nomination.

“Harris will be easier to beat than Joe Biden would have been,” Mr Trump told CNN shortly after Mr Biden’s announcement on Sunday.

Mr Trump’s campaign has signalled it will tie her as tightly as possible to Mr Biden’s immigration policy, which Republicans say is to blame for a sharp increase in the numbers of people crossing the southern border with Mexico illegally.

The second line of attack will revolve around the economy, they say.

Public opinion polls consistently show that Americans are unhappy with the high food and fuel costs and interest rates that have made buying a home less affordable.

“She’s the co-pilot of the Biden vision,” said one Trump adviser, speaking on condition of anonymity during last week’s Republican National Convention, where a unified party anointed Mr Trump as its nominee in the White House race.

“If they want to switch to Biden 2.0 and have ‘Cackling’ Kamala at the top of the ticket, we’re good either way,” the adviser said, repeating an insult the campaign has been trying out for weeks focused on how the vice-president laughs.

Make America Great Again Inc., a super PAC backing Mr Trump, said on Sunday it was pulling anti-Biden television ads that had been set to run in the battleground states of Arizona, Georgia, Nevada, and Pennsylvania and replacing them with an ad attacking Ms Harris.

The 30-second ad accuses Ms Harris of hiding Mr Biden’s infirmity from the public and seeks to pin the administration’s record solely on her.

“Kamala knew Joe couldn’t do the job, so she did it. Look what she got done: a border invasion, runaway inflation, the American Dream dead,” the narrator says.

Mr Trump, known for using insulting and sometimes offensive language to attack his opponents, gave supporters at a rally in Michigan on Saturday a taste of the insults he is likely to fling at Ms Harris in the coming days.

“I call her laughing Kamala. You ever watch a laugh? She’s crazy. You can tell a lot by a laugh. She’s crazy. She’s nuts,” he said.

The Democratic Party has yet to determine how to move forward, and there is as yet no guarantee that Harris will emerge as the party’s nominee even with Biden’s endorsement.

Ms Harris, as the Democratic nominee, would alter the race in perhaps unforeseen ways, political strategists said.

A 59-year-old Black and Asian-American woman would fashion an entirely new dynamic with Mr Trump, 78, offering a vivid generational and cultural split-screen.

The United States has yet to elect a female president in its 248-year history.

Rodell Mollineau, a Democratic strategist and longtime congressional aide, said Ms Harris could mount “a more energetic campaign with excitement from younger voters and people of colour” after Mr Biden struggled to energise these important Democratic Party voting blocs.

A former prosecutor, California attorney general, and a former U.S. senator, Ms Harris, could use “her years of litigation experience to effectively prosecute Trump in the court of public opinion,” Mr Mollineau said.

Chip Felkel, a Republican strategist, cautioned that it would be a mistake for the Trump campaign to assume Ms Harris could serve as a simple stand-in for Mr Biden because of her potential appeal to different parts of the electorate.

Recent polls have shown Ms Harris to be competitive with Mr Trump.

In a hypothetical head-to-head matchup, Ms Harris and Mr Trump were tied with 44 per cent support each in a July 15-16 Reuters/Ipsos poll.

Before Sunday, the Trump campaign had already begun discussions about how they would redeploy campaign resources should Biden drop out of the race, according to a source with direct knowledge of the matter.

Jeanette Hoffman, a Republican political consultant, said even with the contrasts Harris would bring to the ticket, her close ties to Biden would be a drag on her candidacy.

Ms Harris “doesn’t represent the change America is looking for,” Ms Hoffman said.

MAGA Inc. CEO Taylor Budowich said his group had commissioned opposition research on several possible Democratic candidates.

“MAGA Inc is prepared for all outcomes of a Democrat Party who has only brought chaos and failure,” he said. 

(Reuters/NAN)