The Democratic Senatorial Campaign Committee hopes to raise nearly $400,000 over the next week in response to Friday’s announcement that Crossroads GPS will spend $20 million attacking President Obama.

The DSCC sent an email warning supporters that the conservative advertising attack campaign has launched in states critical to Obama’s reelection and to Democrats retaining control of the Senate. But it doesn’t appear Senate Democrats will come close to matching the conservative advertising effort dollar for dollar. 

{mosads}“Crossroads GPS, one of Karl Rove’s outfits, just launched a $20 million — you read that right — ad buy hitting President Obama and Democrats in key swing states,” the DSCC’s Guy Cecil wrote in a message to potential donors. 

Cecil noted that Bob Perry, who underwrote the 2004 Swift Boat Veterans for Truth ads that helped sink Sen. John Kerry’s (D-Mass.) presidential bid, has funded Rove’s political efforts.

“It’s a huge buy, but we can fend them off in the states they’re targeting IF we hit this fundraising goal on Thursday. We have 5 days left; we’re $358,000 short,” he wrote.

Rove and former Republican National Committee Chairman Ed Gillespie reported to Federal Election that their affiliated group, American Crossroads, received $500,000 from Perry in late February.

Crossroads GPS will launch a $5 million television advertising campaign on national cable news channels and local network affiliates in Colorado, Florida, Iowa, Missouri, Montana, Nebraska, North Carolina, New Mexico, Nevada and Virginia. The ad campaign will begin Monday and last two weeks.

There are competitive Senate races in seven of those states: Florida, Missouri, Montana, Nebraska, New Mexico, Nevada and Virginia.

“Can you help? Even $5 or $10 will help counter the GOP’s flood of corporate cash?” the DSCC wrote to supporters.