Democrats have a "sizeable advantage" over Republicans in fundraising through the end of 2013, end-of-year Federal Election Commission reports filed Friday show.

The Wall Street Journal examined FEC data for the most competitive senate and congressional races, and found that Democratic candidates had raised $42.3 million in 2013 compared to $34.8 million by Republicans, and had about $6 million more in the bank going into the first part of the 2014 election cycle. The Democratic Senatorial Campaign Committee outraised the National Republican Senatorial Committee by $16 million in 2013.

But the biggest surprise might be how far Republican strategist Karl Rove has fallen from grace among Republican donors.

With no contest for either the White House or Congress in 2013, a slow fundraising year might be expected. But the gap for Rove's groups — American Crossroads, Crossroads GPS and the Conservative Victory Project — remains stunning in comparison to receipts for upstart Tea Party-oriented campaign groups.

Rove's three groups took in $6.1 million in 2013, Politico notes, while American Crossroads alone received $99.1 million in 2012. All three together raised about $325 million during the Romney campaign and the battle for congress. Rove-backed candidates failed almost everywhere -- more than 95 percent of money spent by Rove's groups ultimately backed losing candidates.

Meanwhile, Tea Party-backed insurgent conservative groups outraised and outspent groups perceived as supporting establishment Republicans. The New York Times noted that FreedomWorks, the Club for Growth Action Fund, the Senate Conservatives Fund, and the Tea Party Patriots raised about $20 million in 2013.

Notably, issue advocacy 501(c)4 organizations like the Koch brothers-backed Americans for Prosperity are not required to disclose their donors or their fundraising activities, leaving a large pool of politically-interested "dark money" unaccounted for.