ASSOCIATED PRESS Sen. Elizabeth Warren is ratcheting up her calls to rid the Democratic Party of big money, a challenge to the other candidates running for the nomination.

Massachusetts Sen. Elizabeth Warren has declared war on one of the fundamental elements of modern-day politics: the high-dollar fundraiser.

In an email to supporters on Monday, the 2020 Democratic presidential candidate pledged not to give additional access to people who donate large sums to her campaign or even to participate in “call time” ― that is, the hours that many candidates spend stuck in a room requesting money from donors over the phone.

“My presidential primary campaign will be run on the principle of equal access for anybody who joins it,” Warren wrote. “That means no fancy receptions or big money fundraisers only with people who can write the big checks. And when I thank the people giving to my campaign, it will not be based on the size of their donation. It means that wealthy donors won’t be able to purchase better seats or one-on-one time with me at our events.”

Warren’s new oath is an escalation of her prior efforts to ensure that small-dollar fundraising is the only politically acceptable way to rake in campaign cash during the 2020 Democratic presidential nominating contest. It’s a rejection of the way that almost every presidential candidate in recent memory ― from Barack Obama to Jeb Bush ― has brought in campaign funds. The senator has previously asked all the Democrats running for the right to challenge President Donald Trump to swear off support from super PACs, which can take unlimited donations, and from corporate PACs, which bundle together donations from a company’s employees and send them to elected officials.

The pledge will also deprive Warren’s campaign of significant funds as she battles as many as a dozen other candidates for the Democratic nomination.

Warren, California Sen. Kamala Harris and Vermont Sen. Bernie Sanders are seen as the candidates with the most potential to bring in small-dollar donations online. Sanders notably raised $6 million in a single day after announcing his campaign last week, and Harris raised $1.5 million in the first 24 hours after announcing her bid. Warren hasn’t released similar fundraising numbers, but she does have $11 million left in the bank from her Senate re-election bid in 2018.

Other candidates including Sens. Cory Booker of New Jersey, Kirsten Gillibrand of New York and Sherrod Brown of Ohio also have a proven appeal to small-dollar donors. But some potential candidates, including former Vice President Joe Biden and former New York City Mayor Michael Bloomberg, have almost no history of raising cash online.

While Warren has challenged the rest of the field to swear off super PACs, corporate PACs and self-funding ― and most candidates so far have entered the race on those terms ― she didn’t issue a similar call for her rivals to ditch big-dollar fundraisers.

But she made clear she would spend her time organizing and rallying voters instead of hobnobbing with the wealthy, which is a powerful message in a Democratic Party increasingly skeptical of its leaders’ reliance on sizable donations from Wall Street and business interests. She noted that studies have shown congressional candidates are often forced to spend more than two-thirds of their time dialing for dollars and that a reliance on big donations has created a system in which 91 percent of contributors in the 2018 election were white.

“For every time you see a presidential candidate talking with voters at a town hall, rally, or local diner, those same candidates are spending three or four or five times as long with wealthy donors ― on the phone, or in conference rooms at hedge fund offices, or at fancy receptions and intimate dinners ― all behind closed doors,” Warren wrote. And she noted, “Making this decision will ensure that I will be outraised by other candidates in this race.”

The cultivation of big donors and bundlers has been a fundamental part of presidential campaigns in both parties for years. Sufficiently large donations were likely to get a lobbyist or supporter face time with the candidates as well as policy and political briefings from staffers. The more a donor gave, the more access they got.

In her email, Warren noted that whoever won the Democratic primary would likely throw all these pledges about restricted fundraising out the window during the general election. Trump’s campaign has worked aggressively to build his online fundraising base, and the GOP donor community that shunned him in 2016 is now more supportive. “We will do what is necessary to match them financially,” Warren wrote.