One of the largest sources of campaign contributions to Senate Democrats during this year's healthcare debate is a physician-owned hospital in one of the country's poorest regions that has sought to soften measures that could choke its rapid growth. The Democratic Senatorial Campaign Committee collected nearly $500,000 at a reception in McAllen, TX, on March 30, mostly from physicians and others affiliated with Doctors Hospital at Renaissance, financial disclosure records show. The event was held at the home of a prominent McAllen developer, Alonzo Cantu, a hospital founder, investor, and board member who has raised prodigious sums from the Rio Grande Valley for an array of Democrats.