Early spending on congressional races shows Senate Democrats reaching for 60 seats and House Democrats making good on their promise to stay on offense.

With less than seven weeks until Election Day, the vast majority of independent expenditures from House and Senate Democrats have gone to offense, according to an analysis by The Hill.

In the Senate, both parties have engaged in six key GOP-held states, while the lone major GOP target, Sen. Mary Landrieu (D-La.), has eluded any national money.

The Democratic Senatorial Campaign Committee (DSCC) also went up with its first ad in top-targeted Alaska on Tuesday, and it might not have to spend anything to win GOP-held seats in New Mexico and Virginia. Combining those three with the six battlegrounds would give Democrats a nine-seat gain and an effective 60-seat filibuster-proof majority.

In all, Democrats have spent nearly $17 million combined, while Republicans have spent only about $5 million, according to a review of Federal Election Commission (FEC) reports.

Independent expenditures are made by separate arms of the party committees and are the main method for them to spend money on candidates, since the amount of money they can coordinate is limited.

The expenditures are still in their infancy this cycle for the major parties’ House and Senate committees, which generally wait until the final months before entering into a race. But a clear trend is emerging as the last of the primaries are held and those expenditures become more and more frequent.

Not counting special elections, the DCCC has spent nearly $4 million so far on independent expenditures, with more than two-thirds going for offense.

The DSCC has been spending more heavily on its targets to this point, spreading nearly $13 million over seven GOP-held seats, according to FEC reports available Tuesday.

House Republicans have spent only about $106,000 thus far, while Senate Republicans announced another $2 million in buys Tuesday, bringing their total for the cycle to about $5 million.

The gap in spending isn’t all that surprising. At the end of July, the Democrats had a 4-to-1 advantage in cash in the House and an $18 million edge in the Senate.

The biggest recipients of national money so far are Oregon, where the DSCC has spent $3.7 million to help financially overmatched state House Speaker Jeff Merkley (D), and Illinois’s 11th district, an expensive open-seat battleground in the Chicago area where the DCCC has spent nearly half a million dollars already. Rep. Jerry Weller (R-Ill.) is not running for reelection.

The DCCC has also spent heavily on two pairs of open seats in Ohio and New Jersey, as well as two Southwestern swing districts — retiring Rep. Rick Renzi’s (R-Ariz.) and outgoing Rep. Heather Wilson’s (R-N.M.).

A pair of New York open seats being vacated by GOPers Vito Fossella and James Walsh have so far received no national money. Those two seats could be House Democrats’ best takeover opportunities, though, and might not need DCCC help.

The DCCC hasn’t been completely on offense, though, spending substantial amounts to shore up a few vulnerable incumbents.

Thus far, the committee has spent $380,000 on Rep. Nick Lampson (D-Texas), $260,000 on Rep. Paul Kanjorski (D-Pa.), $190,000 on Rep. Harry Mitchell (D-Ariz.) and $120,000 on Rep. Jerry McNerney (D-Calif.). No other Democratic incumbent has received more than $50,000 thus far.

In addition to its efforts to unseat Sen. Gordon Smith (R-Ore.), the DSCC has also spent more than $2 million already against both Sens. John Sununu (R-N.H.) and Elizabeth Dole (R-N.C.).

Dole’s race has emerged as an unlikely early battleground, as state Sen. Kay Hagan (D) continues to rival her in numerous polls. The National Republican Senatorial Committee (NRSC) has spent $1.4 million on Dole so far, making North Carolina its most expensive state.

The other three states where both committees have engaged are Mississippi, Colorado and Minnesota.
Neither committee has spent independent money on two GOP-held seats — New Mexico and Virginia — that have polled with Democrats leading by wide margins.

Alaska was polling similarly, but looks like it might be in play again now that home-state Gov. Sarah Palin is the GOP vice presidential nominee. At the same time, it will be risky for the NRSC to spent money on indicted Sen. Ted Stevens (R-Alaska) as his corruption trial proceeds.

The DSCC has also listed Kentucky and Maine as top races.

In Maine, it has spent a comparatively small sum — $170,000 — against Sen. Susan Collins (R), who holds a solid lead over Rep. Tom Allen (D). In Kentucky, the committee has not spent anything, but self-funding businessman Bruce Lunsford (D) has been able to stay on the air with his own advertising.

The committees generally refrain from commenting on the expenditures, citing the independence of the operation.

Mary-Sarah Kinner, a spokeswoman for the NRSC, wouldn’t directly address the expenditures but said voters are just starting to pay attention to Senate races and that the committee will adjust accordingly.

“Races will change, races will tighten and other races will begin to widen,” Kinner said. “But when it comes to November, we’re cautiously optimistic that we will be where we need to be.”

Chart (.PDF) Editor’s Note: In chart some figures have been rounded