WASHINGTON – When the next Congress cranks up in January, there will be more women, many new faces and 11 fewer tea party-backed House Republicans from the class of 2010 who sought a second term.

Overriding those changes, though, is a thinning of pragmatic, centrist veterans in both parties. Among those leaving are some of the Senate’s most pragmatic lawmakers, nearly half of the House’s centrist Blue Dog Democrats and several moderate House Republicans.

That could leave the parties more polarized even as President Barack Obama and congressional leaders talk up the cooperation needed to tackle complex,
vexing problems such as curbing deficits, revamping tax laws and culling savings from Medicare and other costly, popular programs.