Charles Koch. Picture: REUTERS
Charles Koch. Picture: REUTERS

Chicago — President Donald Trump continued his attacks on mega donor Charles Koch, who has built one of the most influential groups in conservative politics, as the pair continue to stake out conflicting visions for the Republican Party.

"Charles Koch of Koch Brothers, who claims to be giving away millions of dollars to politicians even though I know very few who have seen this (?), now makes the ridiculous statement that what President Trump is doing is unfair to ‘foreign workers’," Trump said in a tweet posted on Thursday.

He added: "He is correct, AMERICA FIRST!"

It was not immediately clear what Trump was referring to. On Sunday, Koch said he worried that Trump’s trade policies could trigger a recession, if they became restrictive enough. The billionaire industrialist was measured in his criticisms, but his top deputies had sharply condemned the president’s leadership style a day earlier.

In two tweets on Tuesday, Trump called brothers Charles and David Koch "globalists" who "have become a total joke in real Republican circles". He also said their political network was "highly overrated".

James Davis, a spokesman for the network, did not immediately respond to an e-mail seeking comment on Thursday. After Trump’s on Tuesday tweets, Davis said: "We support policies that help all people improve their lives. We look forward to working with anyone to do so."

The Koch brothers did not support Trump in 2016 and the two sides have clashed over Trump’s opposition to long-held conservative beliefs on government spending and free trade, as well as a more welcoming stance held by the network on immigration. But Trump has demonstrated a tight hold over GOP voters that has made Republican politicians wary of crossing him.

Keeping the network happy is important to Republicans, especially in election years. It plans to spend about $400m on state and federal policy and politics during the two-year cycle that culminates with November’s balloting, a 60% increase over 2015-16. Besides trying to influence electoral politics, the organisation also works on education, criminal justice, workforce and poverty issues.

Charles Koch, 82, is chairman and chief executive officer of Koch Industries.