Karl Rove's American Crossroads has drawn a lot of attention for its high-profile fundraising and lavish spending on congressional races. But Rove's group, it turns out, isn't the only one at the plate. A detailed analysis of campaign spending by cloak-and-dagger "shadow groups" -- who are able to shift vast sums of money into campaign advertising and affect the outcome of competitive races -- show that the groups collectively have spent nearly a quarter of a billion dollars in the 2010 cycle.