So far, President-elect Barack Obama’s Cabinet and White House appointments have had a “dog in the nighttime” effect on Republicans. The selections, like the intruder in the Sherlock Holmes mystery, haven’t made them bark.

The reason the dog remained quiet, Holmes deduced, is because he knew the late-night visitor who stole the race horse Silver Blaze before a major race. The dog’s sanguine reaction helped the fictional detective narrow the list of suspects.

Similar to the stable dog, Republicans have kept quiet—or even voiced support—of Obama’s choices for economic and national security leadership positions.

The people Obama tapped to head the Treasury, the National Economic Council and his Economic Recovery Advisory Board—Timothy Geithner, Lawrence Summers and Paul Volcker, respectively—are generally centrist and soothing to Republicans.

On national security, Obama even allowed a Republican, Secretary of Defense Robert Gates, to remain in place for the next year.

Having stayed in the middle of the road on economic and national security personnel, Obama is now free to swerve to the left in selecting a secretary of labor. With this choice, he is likely to satisfy progressives—formerly known as liberals—and organized labor.

Both groups played a significant role in putting Obama in office, and they’ve been patiently waiting for a Cabinet appointment that they can celebrate. Republicans will growl.

I’m not going to guess who Obama will place at the Labor Department helm, but it almost certainly will be someone who supports the Employee Free Choice Act, the so-called card-check bill, and who vows to use the agency’s regulatory and enforcement mechanisms to crack down on employers.

In an Obama administration, the Department of Labor, along with the Equal Employment Opportunity Commission and the National Labor Relations Board, “will be emboldened (and further funded with bigger budgets) to pursue aggressive investigations against employers for wage and hour violations, unfair labor practice charges and charges of unlawful discrimination,” writes Gerald L. Maatman Jr., a partner at Seyfarth Shaw in Chicago, in a November 24 report.

Two people whose names have been mentioned as potential Labor secretaries—former Rep. David Bonior and NLRB member Wilma Liebman—recently spoke in favor of the unionization bill at a November 20 event in Washington.

Greater unionization would be a step toward “enlightened capitalism,” Bonior said. In such an economy, workers on Main Street will get as much attention and support as financiers on Wall Street.

More Americans will rise to the middle class through the wages and benefits they receive in collective bargaining, according to Bonior.

“It’s not a coincidence that the widening income gap in the United States of America tracks the decline in union density,” Bonior said.

Liebman foresees a major overhaul of employment law during the Obama administration, with the card-check bill serving as the foundation.

“Everything starts with being able to win union representation in the workplace,” she said.

Bonior has ruled himself out of contention for labor secretary. Liebman said she won’t turn down a job she hasn’t been offered. Regardless of who takes over the department, it is likely to play a prominent role in Obama’s effort to address economic woes.

In fact, by giving Obama a decisive electoral vote victory, Americans may be signaling that they want Washington to be more involved in the economy.

“With the election occurring against the backdrop of housing, financial and automaker crises, a consumer confidence rate at the lowest level in recorded history, a plunging stock market that eviscerated 401(k) plans and other retirement savings accounts, as well as the highest unemployment rate since 2001, the electorate is increasingly distrustful of the private sector and more willing to rely on government initiatives to secure their future,” Maatman writes.