Sen. Elizabeth Warren Elizabeth WarrenOvernight Defense: Appeals court revives House lawsuit against military funding for border wall | Dems push for limits on transferring military gear to police | Lawmakers ask for IG probe into Pentagon's use of COVID-19 funds On The Money: Half of states deplete funds for Trump's 0 unemployment expansion | EU appealing ruling in Apple tax case | House Democrats include more aid for airlines in coronavirus package Warren, Khanna request IG investigation into Pentagon's use of coronavirus funds MORE’s (D-Mass.) presidential campaign is launching TV and digital ads in four early voting states as the progressive senator continues to stay at the top of the field.

The eight-figure ad buy announced Tuesday in an email to supporters will fund ads in Iowa, New Hampshire, Nevada and South Carolina, according to multiple reports.

The ads reportedly range from 15 to 30 seconds, with a focus on ridding Washington of corruption, featuring images of President Trump Donald John TrumpFederal prosecutor speaks out, says Barr 'has brought shame' on Justice Dept. Former Pence aide: White House staffers discussed Trump refusing to leave office Progressive group buys domain name of Trump's No. 1 Supreme Court pick MORE, Vice President Pence and Senate Majority Leader Mitch McConnell Addison (Mitch) Mitchell McConnellDemocratic senator to party: 'A little message discipline wouldn't kill us' House to vote on resolution affirming peaceful transition of power Republican lawyers brush off Trump's election comments MORE (R-Ky.).

“I'm Elizabeth Warren. I know what's wrong. I know how to fix it. And I'll fight to get it done,” the senator says to close each ad. ADVERTISEMENT

"At the start of this campaign, we laid out how Elizabeth is going to win the primary and the general election — by identifying the deep problems the country faces, creating plans to solve them, and building a grassroots movement to win in 2020 and make big, structural change in 2021 and beyond," campaign manager Roger Lau wrote to supporters, according to CNN.

"As we head into the fall, here's how we'll build on our progress, build out our team, and keep growing the movement that will elect Elizabeth and elect Democrats up and down the ballot next November."

The Hill has reached out to the Warren campaign.

The ad buy comes as polls show Warren gaining momentum as a top challenger to front-runner Joe Biden Joe BidenFormer Pence aide: White House staffers discussed Trump refusing to leave office Progressive group buys domain name of Trump's No. 1 Supreme Court pick Bloomberg rolls out M ad buy to boost Biden in Florida MORE.

A poll released Saturday had Warren ahead of the former vice president, who has been leading the crowded field, by 2 points in Iowa. A Nevada poll released Tuesday had Biden with a slim 4-point lead over Warren.

Her campaign has also touted large crowd sizes at her events — estimating 20,000 people attended her rally in New York City last week.

The ads aren’t the only new investment for the Warren campaign. The campaign reportedly said it’s putting resources on the ground, including hiring new state directors and organizers, in some later states.

The campaign is focused on aiding states with key House, Senate and state legislature races in 2020.

"That includes states like Illinois and California, where Democrats won a whole bunch of House seats in 2018 in close elections that we'll need to defend. It also includes states like Maine, which has a competitive Senate race, and Georgia, where there will be two Senate seats up for election,” Lau wrote.