Colorado Springs — Groups backed by Charles and David Koch warned here on Saturday that Medicaid expansion under Obamacare has had disastrous healthcare consequences for millions of people around the country, and said the failure of congressional legislation to tackle the problem remains a top concern of theirs.

“Medicaid expansion is a big piece of it, because overall what we’ve seen is it’s crowded out care for those that are truly the most vulnerable, and added able-boded individuals to that,” Freedom Partners executive vice president James Davis told reporters when asked what most worries them about the Senate bill.