McConnell (Creative Commons)

Earmarks allow lawmakers to direct money already appropriated to federal agencies to specific projects, usually ones in their own states or districts.

During the past few years, earmarks have come to be seen as examples of the wasteful spending that plagues Congress. A handle of earmarks each year fund projects seen as frivilous or useless. But some lawmakers, including Senate Majority Leader Harry Reid, have said earmarks serve constituients well and keep power in the hands of Congress rather than the White House.

McConnell, who was re-elected Tuesday as the Republican leader in the Senate, said earlier this month that banning earmarks won't cut anything from the budget, which is why his support in Tuesday's vote was surprising. The money is already planned to be spent anyway, so cutting earmarks doesn't affect the budget.

President Barack Obama  agreed with McConnell, saying banning earmarks is just the start of a reform process to reduce federal deficits.

House Republicans have a ban in place already. Neither House nor Senate Democrats have followed suit, though Sen. Claire McCaskill (D-Mo.) is leading a charge to throw an earmarks ban into a completely unrelated bill that the full Senate is expected to consider this week. If such an amendment was approved and the full bill was passed, the ban on earmarks would become part of the Senate's official rules.

Reach executive producer Paresh Dave here. Follow him on Twitter: @peard33.