Many people(1) are quietly concerned about not being able to find public toilet facilities when they travel or participate in out of doors activities.  While hesitant to come forward, many  appreciate those who address the problem.  Most likely this is an issue that, carefully handled, can draw votes.   
(1) See 'Who are the Restroom Challenged' for additional information

Examples of senior level elected official safely leveraging peoples desire to have public toilet facilities 

Audio from President George Bush  ... we want there to be a visitor's center that's worth going into. We want the toilets to flush.... ... so that the people, when it comes to using their own park, are able to do so in a comfortable way. 
Source:  White House Office of the Press Secretary Aug 15, 03  Strengthening and Caring for America's National Parks  

President Clinton and Vice Presidents Gore's Airline Passenger Fair Treatment Initiative
The Clinton-Gore initiative will help passengers who encounter changing travel conditions and problems with their flights. Airlines will be required to develop policies on notifying passengers about flight delays, cancellations and diversions; providing food, water and restroom facilities during ground delays; ...  
Source: THE WHITE HOUSE AT WORK Wednesday, March 10, 1999  http://clinton3.nara.gov/WH/Work/031099.html

California Politician who won office based on a restroom issue.
Dr. March Fong Eu became famous for smashing a toilet bowl on the state Capitol's steps during her successful campaign to ban pay toilets, which she said discriminate against women.  She was elected to the California legislature in 1966. Eu served four terms and was elected California secretary of state in 1974, making her the first Asian American woman ever elected to a state constitutional office in the United States.  
Source: www.infoplease.com/ipa/A0880736.html 

An indication that most politician don't get it 
Most recently there have been numerous news stories about the media's anger with the lack of public toilet facilities they were provided at the National Democratic Convention.
Source: http://news.bostonherald.com/localRegional/view.bg?articleid=35696

Additional Media response

Citizens Surveys

The Presidents Council on Fitness and Sport found that when surveyed, people asked to list infrastructure upgrades that would help them participate in outdoor fitness activities respondents seldom list restrooms.   If, however, restrooms are listed as a choice, they typically are ranked high.

An example is a recent (March to June of 2002) ETC survey conducted for Arlington County Virginia.   The community attitude and interest survey helped determine citizen usage, satisfaction, needs, and priorities for the parks and recreation system. Respondents were asked to pick three (3) out of an extensive list of improvements they would most like to have made to the parks. Year-round restrooms was the second highest choice.   

  Arlington County Parks & Recreation Survey
  (Full Exec Summary)      ( HTML Version )
  Arlington County Parks & Recreation Survey 
  (Pages 1 & 17) 

... Perhaps we were all a little hasty in saying that women are the real power behind the throne. Especially when women have to often wait a long, long, long time in line for a chance at the throne... ... Frankly, there are no equal rights for women when it comes to one of the mothers of all necessities -- the number of toilets... ... Smith, [Democratic Rep. Tommy Smith] who has three female co-sponsors for the bill, [more toilets for women] told the AP that even though the bill zeros in on government buildings he believes that all public restrooms should follow suit. "This is a serious, serious problem," he said. "If you talk to any woman, she'll tell you it's a serious problem." ...   

... Somewhere a political hack will read about this and make it a "campaign issue." Now, the beauty of campaign issues are that for about three years no one gives a fuzzy toilet top about certain things that matter to the average soccer mom/voter. Come an election year, however, what a soccer mom thinks really starts to become very, very important. The political hacks (they are called consultants in press releases) will look at all the potential women voters out there and realize the same thing that Rep. Smith did. So, in this presidential election season, it would be the smart candidate ...

The Kentucky New Era "More toilets can win elections"  February 26, 2004 Hopkinsville, Kentucky 
Copyright © 2000, Kentucky New Era, All Rights Reserved.

Additional Media 

Few complain but many care... 

The campaign to have the Washington Metropolitan Area Transit Authority allow customer use of Metrorail station restrooms was led by the chair of the WMATA Operation Board who was also a municipal elected official.   He was surprised that the significant media coverage of the effort was producing no feedback from his constituents, pro or con.   Some month later, in an unrelated event, he attended a community meeting where the majority of attendees were not receptive to his position.  Even in that 'cold' environment, when, at the end of the meeting, it was mentioned that he was the official pushing to have the metrorail restrooms his constituents broke into applause and cheers.   

When giving unrelated Metroped presentations, particularly if to women and seniors (men and women) I have the same experience.   Below is a brief audio segment that documents the response. 

 Acknowledgement of Restroom Success [WAV Audio File]  Mt Vernon Town Mtg 1/31/04