Putting their friendship above party, Democratic Sen. Daniel Inouye (Hawaii) will headline a fundraiser today for one of the Democrats’ top targets this cycle, Republican Sen. Ted Stevens (Alaska).

Inouye, who chairs the Commerce, Science and Transportation Committee, on which Stevens is the ranking member, is the “special guest” at the noon event at 101 Constitution Ave. NW. According to the invitation, the lunch is organized by several high-profile lobbyists, including Stevens’ former top aide, Lisa Sutherland. The fundraiser seeks $1,000 in contributions from individuals and $5,000 from political action committees to aid Stevens’ bid for an eighth term this fall.

Inouye and Stevens have long been allies and senior appropriators, and have reputations for putting their personal and working relationships ahead of party politics. In the 2004 cycle, Stevens similarly helped Inouye raise thousands of dollars for his re-election, which was not seriously contested.

But this cycle is different since Stevens is under federal investigation as part of a wide-ranging corruption probe in Alaska. Additionally, Senate Democrats have set their sights on picking up as many as nine seats this fall — including Stevens’ — in the hope of holding 60 seats, the number needed to overcome filibusters.

Anchorage Democratic Mayor Mark Begich recently announced his campaign to unseat Stevens, the longest-serving GOP Senator. Democrats heavily recruited Begich to enter the race, which is expected to be costly and competitive.

Calls to Inouye’s D.C. office and Stevens’ campaign headquarters in Alaska were not immediately returned Wednesday morning. A spokesman for Majority Leader Harry Reid (D-Nev.) declined to comment.

Wednesday’s fundraising event is the latest example of politics blurring party lines in the Senate. Last cycle, Sen. Susan Collins (R-Maine) endorsed then-Democratic Sen. Joseph Lieberman (Conn.) in his re-election bid, and this cycle Lieberman has returned the favor in backing his Homeland Security and Governmental Affairs Committee colleague. Lieberman, now an Independent Democrat, chairs that panel. Collins is the ranking member.

Lieberman also has endorsed Republican Sen. John McCain (Ariz.) for president, and has been barnstorming the country on behalf of his fellow Senator.