Credit for this idea goes to my son, Ryan. This is a strategy for getting to a filibuster-proof Senate.
President Obama is interested in a bipartisan administration. To that end, he should appoint Senator Olympia Snowe to a post, maybe heading up the Small Business Administration, and Senator Arlen Specter to head up Immigration reform. Both would be replaced by Senators appointed by Democratic governors. These seats represent Democratic leaning states, so the appointees would win in a subsequent special election.
The only question is how to convince the two of them to accept the appointments. Their progressive leadership as Republicans in these two areas that are important to Republicans and to them personally would make it easier to enact appropriate legislation. The prospect of making a difference in these areas might be enough to convince them to accept.