The House deposed Bolton, and Bolton refused to appear. Then he said he'd only testify if subpoenaed and if a court ruled on the immunity issue and compelled his testimony. House Democrats declined to subpoena him, saying they didn't want to wait for a court to decide the issue.

It's anyone's guess why Democrats didn't want to go through the courts. Maybe they thought it would take too long, with expected appeals that could go all the way to the Supreme Court. Maybe they were afraid of a loss that would create a precedent too strongly in favor of presidential power. Maybe they thought they had a better chance of getting testimony in the Senate, or that it could happen more quickly there. Maybe they thought they already had enough evidence of corruption.