A president's endorsement is usually considered a boon to the candidate he's backing. Now President Bush wants to know whether ads by candidates that mention his support count as a donation to his campaign.

Bush's re-election campaign and a House candidate from Kentucky want the Federal Election Commission (search) to decide whether such ads count as contributions to Bush when run close to elections in which he appears on the ballot.

Alice Forgy Kerr (search) is running in a special election Feb. 17 to fill a seat vacated by Republican Ernie Fletcher (search), who was elected governor; Bush is a candidate in Kentucky's May 18 presidential primary.

Kerr's campaign began airing an ad this month that shows Bush and Kerr, a Republican state senator from Lexington, walking together at the White House and shaking hands. Kerr's campaign also wants to run ads telling voters that Bush is endorsing her.

A new campaign finance law set new rules on the coordination of federal election activities. In light of that, the Bush and Kerr campaigns are asking for FEC guidance on whether Kerr can pay for the ads as she plans, or whether the two candidates should share the cost.

They also asked whether and to what extent Bush's campaign can discuss the content and use of the ads with Kerr's campaign. They also want to know how far the ads can go in referring to Bush policies or to Kerr's support for them without counting as donations to Bush, subject to federal limits.

The campaigns asked the FEC to rule by the end of the month.

Kerr is running against Democrat Ben Chandler (search).