Senate Democrats are seriously considering an Employee Free Choice Act compromise proposal from Sen. Dianne Feinstein, D-Calif., that would use mail-in elections to preserve the secret ballot.

Her proposal would replace the card-check provision, which would allow workers to unionize if a majority signed authorization cards and strip a company's ability to demand a secret ballot election. "It's a secret ballot that would be mailed in ... just like an absentee ballot. The individual could take it home and mail it in," Feinstein said. If a majority mailed the ballots to the National Labor Relations Board, the NLRB would recognize the union.

Sen. Tom Harkin, D-Iowa, who is leading negotiations, said Feinstein's proposal was promising. "It has the good elements of protecting the secret ballot, so people can still do it in private, but then it also takes away the harassment issue. That's why I think her proposal has a lot of merit," Harkin said.