Sen. Scott Brown (R-Mass.) cast his first major vote today, helping Republicans maintain a filibuster against President Obama's nominee to the National Labor Relations Board.

Brown opposed ending debate on the nomination of Craig Becker, a former lawyer for the Service Employees International Union (SEIU) who has received stiff opposition from business groups and Republicans.

The final vote was 52-33, falling short of the 60 needed to end debate and move to a final vote.

President Obama has blasted Republicans for filibustering nominees like Becker. The vote suggests Brown will stick with his caucus on controversial party-line votes.

Many suspect that Brown asked to be sworn-in last week--earlier than originally planned--so he could be present to add a crucial vote against Becker, whose nomination has been pending since the summer.

Republicans have argued that Becker will help the NLRB circumvent Congress to impose "card-check" provisions, which would make it easier for unions to form new chapters. Labor groups have so far tried unsuccessfully to push the proposal through the legislative process.

Becker assured Senators he would operate within the boundaries of the law.

In the end, the timing of Brown's swearing-in may not have mattered, since Sen. Ben Nelson (D-Neb.) announced yesterday that he would join Republicans in opposing Becker.