Obama campaign: http://www.barackobama.com

WASHINGTON (AP) – Presidential candidate Barack Obama is using his popularity to help give down-ballot Democrats a boost, with plans to back House and Senate candidates in radio commercials during the campaign’s final days.

Obama’s campaign is working with those charged with building Democratic majorities in the House and Senate to carefully pick which races and which audiences are best to target for additional help.

“In different states, we ask for different things, and they have been great,” said New York Sen. Chuck Schumer, head of the Democratic Senatorial Campaign Committee.

Obama has a particular interest in helping Senate candidates, since it’s a longshot possibility that they could reach 60 seats — enough to prevent Republicans from blocking Democratic legislation.

Some Democrats have suggested that Obama should start donating from his record fundraising haul to help down-ballot candidates and spend the final days traveling to states with contested Senate races. But those are not steps campaign officials say he is going to take when he’s still in a close race for the White House against Republican John McCain.

“I spoke to Barack Obama yesterday,” Schumer said Wednesday, “and I said to him, ‘You have been great and you have helped us in all the ways we have asked.'”

At Schumer’s request, Obama cut an ad encouraging voters to back Senate candidate Jeff Merkley of Oregon, a state Obama is expected to easily win and where Merkley is looking to unseat Republican Sen. Gordon Smith. That’s the only television ad Obama’s done for another candidate in the general election, but his campaign said Obama is recording radio ads for a handful of congressional candidates.

A personal show of support from Obama may not be helpful to Democratic candidates in conservative districts. In Alabama, Republican House candidate Jay Love is running an ad suggesting that Democratic opponent Bobby Bright supports Obama.

“Teams matter,” an announcer says over an image of the Obama-Biden campaign sign altered to say “Obama-Bright.” ”Bobby Bright is on a tax-and-spend team we can’t afford.”

Obama’s biggest boost for down-ballot candidates could come from his robust organizing machine. The higher Obama’s organization can turn out blacks and other Democratic voters, the more likely challengers like Kay Hagan in North Carolina, Ronnie Musgrove in Mississippi and Jim Martin in Georgia will be able to take over seats held by Republicans.

Obama has sent e-mail to millions of supporters across the country, encouraging them to volunteer and vote for local candidates. He and running mate Joe Biden have also sent fundraising appeals for the congressional campaign committees, and Obama has signed off on the Democratic National Committee taking a $10 million line of credit to split between the House and Senate efforts.

Since the Democratic National Convention, Obama has contributed more than $21 million to state party committees, including nearly $4 million to the Florida Democratic Party. The roster of recipients of his biggest donations reads like a map of the presidential election battlegrounds, but he has also contributed smaller amounts to states in the periphery of the contest.

Another way that Obama has been helping some candidates is by inviting those running in the battleground states where he is campaigning to address his events before he arrives. Obama draws crowds that the candidates could never generate on their own, like the 90,000 who came out to see the presidential contender in Colorado on Sunday and heard from Rep. Mark Udall, running for the Senate.

Obama rarely appears on stage with down-ballot candidates, but he often gives them a shout-out and encourages his supporters to vote for them as well. There are exceptions, though. Last week in Florida he appeared on stage with three Democrats running for Congress in South Florida against entrenched Republicans.

He also appeared twice last week on stage with former Virginia Gov. Mark Warner, now running for the Senate — but Warner is comfortably ahead and may be there more to help Obama than vice versa. Warner is running a radio ad encouraging Virginians to support Obama.