The Senate will debate and vote on a bill this summer that would remove a union's long-standing privilege in most states to force workers to choose either to pay union dues or lose their jobs. The right-to-work law would also preserve the rights of workers to join unions if they so wished. Twenty-one states now have such laws.

• Private sector unions now raise $4.9 billion each year from workers through mandatory dues.

• That compares with only $1.2 billion collected by unions through voluntary dues.

• In 1993, the average post-tax income in right-to-work states was $36,540 -- compared to $33,688 in states without right-to-work laws.

• In 1992, right-to-work states attracted 57 percent of all new or expanded company facilities.

The unionized share of the private sector workforce has been declining for four decades in the U.S.

• In 1983, 18.5 percent of private sector payroll workers were covered by a union contract, and 16.5 percent formally belonged to a union.

• By 1994, those figures had declined to 11.9 percent and 10.8 percent.

A survey last year indicated that 77 percent of respondents favored right-to-work laws, with only 17 percent favoring forcing new hires to join a union.