Democratic presidential candidate Hillary Clinton talks with Virginia Gov. Terry McAuliffe (D) after an Oct. 2015 rally in Alexandria. His relationship with the Clintons has helped his fundraising efforts. (Melina Mara/The Washington Post)

The very day that Gov. Terry McAuliffe dismissed critics of a deal he struck on guns as meddling New Yorkers, the Democratic Party of Virginia reeled in its biggest donation of the year — from another New Yorker.

Philip Munger, son of a Berkshire Hathaway billionaire and resident of New York with no obvious connection to the commonwealth, gave the party $250,000 on Feb. 9, according to the Virginia Public Access Project, a nonprofit, nonpartisan organization.

Munger’s donation came on top of hefty amounts of money he gave to the Virginia party last year. He supplied $1 million of the $1.7 million in direct donations that the party took in for state races in 2015 — raising concern among some Democrats that the party was overly reliant on a single donor.

The most recent gift came as McAuliffe (D) spoke dismissively of Everytown for Gun Safety, a group founded by former New York mayor Michael R. Bloomberg. Everytown was a close ally of McAuliffe’s as recently as last fall, when it bankrolled a $2 million ad campaign in a failed attempt to help his party win the state Senate. But the organization turned on McAuliffe after the governor struck a surprise deal with Republicans that expands the right to carry concealed weapons in exchange for tighter gun restrictions on domestic abusers and voluntary background checks at gun shows.

The same day Munger wrote his check, McAuliffe and his spokesman struck back at Everytown as a group of out-of-state activists who did not have Virginia’s true interests at heart. “Everybody supports [the gun deal],” McAuliffe said, “except one gun-safety group out of New York City.”

Emily Bolton, a spokeswoman for the state Democratic Party, said the organization welcomes donations from all over. “There are lots of reasons why donors want to fund programs here in Virginia,” she said. “Our influence and status as a swing state reverberates far beyond the commonwealth.”

David D’Onofrio, spokesman for the Republican Party of Virginia, said the continued reliance on Munger suggests a lack of enthusiasm for presidential hopeful Hillary Clinton and other Democrats.

“Her own party has to go outside of Virginia once again because there’s a serious enthusiasm gap for Democrats in Virginia about this presidential race, about this governor and about this party,” D’Onofrio said.

A spokesman for McAuliffe, Brian Coy, referred questions to party officials.

Munger, who has been a substantial donor to Clinton and President Obama, did not respond to a request for comment. He is the son of Charles Munger Sr., Warren Buffett’s partner in Berkshire Hathaway. One of his siblings, Charles Munger Jr., is a Stanford physicist and moderate Republican credited with propping up the California GOP for the past decade.

Despite his largesse to the Virginia Democratic Party, Munger is largely an unknown in Virginia political circles. Several prominent Virginia Democrats expressed surprise in October, when The Washington Post reported his outsize role in party fundraising.

Some Democrats praise McAuliffe for being able to tap contacts he developed as a Democratic National Committee chairman and a longtime friend of — and fundraiser for — former president Bill Clinton and his wife, Hillary Clinton. Being able to hit up a single, super-rich source for a string of contributions is political moneymaking at its most efficient, these backers say, leaving McAuliffe more time to govern.

But the fundraising approach also runs counter to the populism coursing through the Democratic base this year, with Democratic socialist Sen. Bernie Sanders (Vt.) posing a surprisingly strong threat to Hillary Clinton in the presidential primary.

Some Democrats also have expressed worry that Munger’s largesse will disappear after McAuliffe’s term is up in January 2018.

Bolton said the party is not relying on Munger’s money to fund day-to-day operations, but rather is using it to bankroll a special project intended to engage voters on legislative issues.

It is difficult to put Munger’s most recent donation into context for the party’s fund-raising so far this year, because reports are not due until April. His contribution was disclosed now only because donations of $10,000 or more must be made public as they come in. Munger’s $250,000 gift is, by far, the largest of the big donations disclosed by the party so far this year. The only big gift reported by the Republican Party is a $10,000 donation from the National Rifle Association.

Aside from transfers from other Democratic accounts, there were only two other such donations since January — $10,000 from Suzann Matthews, a Democratic donor from McLean, and $30,000 from DGA Action, a super PAC linked to the Democratic Governors Association.