WASHINGTON (AP) — Several big corporations have reaped millions of dollars from “Obamacare” even as they support GOP candidates who vow to repeal the law. This condemn-while-benefiting strategy angers Democrats, who see some of their top congressional candidates struggling against waves of anti-Obamacare ads partly funded by these companies.

Among the corporations is a familiar Democratic nemesis, Koch Industries, the giant conglomerate headed by the billionaire brothers Charles and David Koch. They and some conservative allies are spending millions of dollars to hammer Democratic senators in North Carolina, Alaska, Colorado, Iowa and elsewhere, chiefly for backing President Barack Obama’s health care overhaul.