Kamala Harris' presidential campaign expressed optimism about its path to the presidency this week, telling reporters in a memo that the change atop the ticket could help the vice president reach a new crop of voters as the campaign plans an aggressive approach to key battleground states.

The extraordinary and rapid ascension of Harris to be the presumptive Democratic nominee "opens up persuadable voters," campaign manager Jennifer O'Malley Dillon wrote.

"The race is more fluid now. The Vice President is well-known but less well-known than both Trump and President Biden, particularly among Dem-leaning constituencies," she added.

O'Malley Dillon said some in this "expanded universe of winnable voters were previously Democrats and support down-ballot Democrats this cycle," a possible reference to the fact that some polls showed Biden with less support than Democrats running further down the ballot.

The memo outlined a plan to capitalize on Harris' appeal with Black, Latino and women voters. It also suggested Harris could attract people who did not vote for the Democratic ticket in 2020 but moved toward Democrats in the years since.

Meanwhile, O'Malley Dillon stressed that the campaign has "multiple pathways" to 270 electoral votes and plans to "play offense" in the competitive Blue Wall states of Michigan, Wisconsin and Pennsylvania, as well as the Sun Belt states of North Carolina, Georgia, Arizona and Nevada.

Since Sunday, Harris has earned the backing of Democratic Party leaders and enough Democratic National Convention delegates to make her the nominee if they kept true to their pledges -- a major milestone for the vice president.

The memo comes a day after the vice president had her first campaign event in battleground Wisconsin on Tuesday, sharply framing her race against former President Donald Trump.