A draft immigration bill from Judiciary Committee Chairman Arlen Specter calls for dramatic increases in legal immigration, far beyond any of the other major proposals now before Congress.Immigration and border security have become the hottest issues in Washington, with senators and members of Congress filing bill after bill to address them. The Senate is preparing for a major debate early next year on an overhaul, including creating a new flow of foreign workers like that contained in the bill by Mr. Specter, Pennsylvania Republican.