WASHINGTON - The Senate rejected a California Democrat's plan to allow the estimated 12 million illegal immigrants in the country to remain, work and eventually become Americans, preserving a fragile bipartisan coalition needed to pass the bill. Several lawmakers who voted against the proposal offered by Sen. Dianne Feinstein (news, bio, voting record) on Tuesday said they did so reluctantly, but out of necessity to ensure survival of the broader immigration bill. The legislation is expected to win Senate passage Wednesday or Thursday. "This legislation is on the edge of the ledge as it is," said Sen. Arlen Specter (news,...