The endorsements candidates seek can range from signs in citizens' yards supporting a candidate or policy proposal to declarations of support issued by major professional, business, and labor organizations. Campaigns use endorsements to communicate to the public that a candidate or policy is worthy of support because individuals and groups with good reputations say so. More specifically, endorsements imply that if you like or respect a specific neighbor or organization, then you ought to support a specific candidate or policy.
For example, the 2002 Democratic gubernatorial candidate Tony Sanchez ran a television ad that showed footage of Republican President George W. Bush and cited a letter from the popular former governor referring to Sanchez as a "great Texan." Sanchez was in effect saying: if you support President Bush, surely you would do well to support me. Of course, the Republicans strongly protested the ad, saying that it incorrectly implied that President Bush supported Sanchez for governor over fellow Republican Rick Perry.
An endorsement from a professional, trade, or industry group often carries with it additional campaign resources. These endorsements hold the promise of the votes of the membership, campaign contributions from the endorsing organization or its members, and perhaps the contribution of time and labor by members. The same holds true even for a yard or window sign: home and business owners communicate their support for a candidate or policy, and they deliver their own votes and, perhaps, campaign contributions.