Tom Steyer plans to spend at least $110 million in 2018 to support Democrats in the midterm elections.
Operatives are installing malware that could give them remote control of parts of the country's power network.
Trump provided no evidence for his claim.
"The Democrats have a death wish, in more ways than one," Trump wrote on Twitter early Thursday morning.
The results of the poll came from 48 Republican-held districts across the country.
Arizona, Florida and Ohio each went for President Trump in 2016.
Virginia Republicans voted to nominate a senatorial candidate with deep connections to white supremacists and anti-Muslim coalitions Tuesday evening. Corey Stewart, a former gubernatorial candidate, confederate statue defender, and praiser of anti-Semites, clinched the nomination.
Seth Grossman, a "Make America Great Again" candidate who clinched a surprise win last week in South New Jersey's Republican congressional primary, is coming under national scrutiny for saying that "the whole idea of diversity is a bunch of crap and un-American."
The movement to abolish ICE is gaining traction in New Mexico's first congressional district, where one of two candidates who support the cause is likely to win Tuesday's primaries.
The Progressive Change Campaign Committee is going after centrist Democrats this cycle, starting with California House candidate Dave Min.
If Democrats let Republicans run with anti-immigrant messaging during the primaries, it could be hard for them to regain control of the narrative in a general election.
President Donald Trump's domestic gag rule could further jeopardize vulnerable Republicans, whose pro-life views could alienate some segments of their base.
Women make up 40 percent of the Democratic Party's House nominees, with 72 of them clinching decisive victories so far this cycle.
Stacey Abrams won her primary in Georgia Tuesday night, bringing her that much closer to becoming the country's first black female governor.
For the first time, polling from Reuters shows Democrats slipping behind Republicans on a generic ballot.
Kara Eastman, a first-time candidate running in Nebraska's 2nd district, edged out the Democratic Party's choice candidate, Brad Ashford.
Senate Minority Leader Chuck Schumer said Democrats would be "relentless" in linking rate increases to Republicans.
One year after Republicans voted to dismantle parts of Obamacare and leave 23 million Americans without health insurance, a new poll showed that voters in key midterm districts were less likely to vote for representatives who attacked it.
Are Democrats losing one of their most loyal voter bases to the Republican Party?