Washington (CNN) Former New York City Mayor Michael Bloomberg will donate $10 million to support Democratic House lawmakers who are facing Republican attacks for supporting President Donald Trump's impeachment, his spokesman Jason Schechter told CNN on Wednesday.

The donation from Bloomberg follows his November announcement to spend $100 million on an anti-Trump ad blitz in key 2020 battleground states.

Bloomberg, a billionaire whose wealth was amassed from a media empire, has also placed millions of dollars worth of television ads across the country to jump start his late entry into the 2020 campaign.

The spending is in line with Bloomberg's backing of Democratic causes for years. During the midterm election cycle last year, Bloomberg's financial firepower helped Democrats wrest control of the House away from Republicans, with the billionaire donating over $100 million to that effort.

But the more recent announcements also appear to make good on a promise by Bloomberg that his costly bid would not divert funds away from the Democratic causes he's been bankrolling for years.

House Speaker Nancy Pelosi welcomed Bloomberg's donation in a statement to CNN on Wednesday.

"In 2018, Mayor Bloomberg was a critical ally in helping House Democrats regain the Majority," said Pelosi, a California Democrat. "Now, the stakes are even higher as we work to make health care more affordable by reducing the skyrocketing cost of prescription drugs, increase wages and root out corruption.

"We welcome and thank Mayor Bloomberg for his support," she said.

The donation comes as House Democrats move forward with articles of impeachment against Trump for his dealings with Ukraine, with the party's leadership charging the President with abuse of power and obstruction of Congress. While Democrats work to move their articles through the House, Republicans are targeting Democrats in districts where Trump is more popular. The conservative American Action Network announced on Tuesday it would expand its attack ads, spending an additional $1.5 million in 10 battleground districts.

Last week, Rep. Tom Emmer, the chairman of the National Republican Congressional Committee, predicted the impeachment of Trump will flip the House in 2020. Rep. Cheri Bustos, the chairwoman of the Democratic Congressional Campaign Committee, dismissed him on Tuesday, saying, "He doesn't know what he's talking about."

But some Democrats are wary of how the vote will affect their reelection races. Hours after the articles were introduced on Tuesday , a few vulnerable House Democrats said outright they planned on voting to impeach Trump, while many Democrats said they were still reviewing them.

"I'm going to do exactly what I was trained to do as a CIA officer, I'm going to look at the full body of information, read it thoroughly and make an objective decision," said Rep. Elissa Slotkin of Michigan. "It's probably the most serious consideration I'll give anything that I'll consider in my one year in Congress."