Pro-business Chamber of Commerce is backing 23 vulnerable House Democratic freshmen for reelection

The Chamber, the world's largest organization promoting business interests, is also endorsing 29 House Republican freshmen, the source also said.

A Chamber spokesman refused to comment on internal processes. The Hill first reported the endorsements.

The Democrats receiving the endorsements are running in some of the most competitive races in the country, including 14 in districts won by President Donald Trump in 2016. They are:

Colin Allred of TexasCindy Axne of IowaAnthony Brindisi of New YorkTJ Cox of California Angie Craig of Minnesota Joe Cunningham of South CarolinaAntonio Delgado of New YorkSharice Davids of Kansas Abby Finkenauer of IowaLizzie Fletcher of TexasJosh Harder of CaliforniaKendra Horn of OklahomaAndy Kim of New JerseySusie Lee of NevadaElaine Luria of VirginiaBen McAdams of Utah Dean Phillips of Minnesota Harley Rouda of CaliforniaXochitl Torres Small of New MexicoGreg Stanton of ArizonaHaley Stevens of Michigan Abigail Spanberger of Virginia David Trone of Maryland

It is the largest number of House Democrats the Chamber has endorsed in at least over a decade. The Chamber only reportedly backed seven Democrats in federal races in 2018, when the party took the House.

The endorsed Democrats have voted in alignment with the Chamber on many issues, including the United States-Mexico-Canada Agreement. Chamber officials have said the criteria deciding which incumbents to back are the Representatives' overall voting record as well as their backing of bills key to the organization.

Still, the endorsements are sure to rankle some of the Chamber's supporters since usually most of its endorsements go to Republicans. Last week, Politico reported that State Chamber of Oklahoma President Chad Warmington wrote a letter to the national Chamber leaders opposing the proposal to back Horn.

But other members supported the move.

Glenn Hamer, the president and CEO of the Arizona Chamber of Commerce, told CNN last week that there are a number of House Democrats who could help the parties come together next year on issues like a free trade agreement with the United Kingdom and comprehensive immigration reform. He also said those members serve as a check on left-wing Democrats such as Massachusetts Sen. Elizabeth Warren.

"I believe the US Chamber is doing the right thing to look to make sure that there's a base of members in the House of Representatives that will give the organization and the job creators a fair day in court," said Hamer.

The endorsements reflect not only the members' records but also a recognition that Republicans are "extremely unlikely" to be able to take back the House this fall, he said.

"For the US Chamber, to have these relationships with more centrist Democrats is important," said Hamer.