You don’t see much in the MSM or political blogosphere about the political priorities and impact of one large political demographic in particular, people with disabilities. Perhaps it’s because the category cuts across many other demographics, race, age, gender, class, sexual orientation etc. with all of the political concerns that come with overlapping identity facets.
With one exception, however, Democrats have demonstrated an edge with this constituency in presidential elections.
In 1992, for example, President George H. W. Bush was that rarest of Republican birds — an actual champion of rights for a group of disadvantaged citizens, in that he strongly supported Americans with Disabilities Act. Yet, here’s what happened in the election, according to Humphrey Taylor, writing for The Harris Poll as its president/ceo:

In the election, Clinton enjoyed a 24 percent lead among disabled voters, which was 19 percentage points better than his 5 point margin of victory. In 1988, George Bush lost the disabled vote by 5 percentage points to Michael Dukakis, which was only 13 points worse than Bush’s 8 point margin of victory.

Taylor goes on to note that people with disabilities were then about 13 percent of the population, roughly the same percentage as African Americans. Other estimates are much higher, including a broader universe of disabilities and “impairments” of varying severity — currently as many as 51 million Americans. Their political impact may be even greater, considering family members who are also affected by their disabilities.
In 1992, however, only about 10 percent of total votes were cast by people with disabilities, notes Taylor. According to Taylor’s analysis of the pro-Democratic tilt in that year:

In 1992, it seems likely that disabled voters — who are much poorer and are much more likely to be unemployed than other voters — were particularly badly hit by the nation’s economic problems for which George Bush was generally blamed.
Furthermore, they were more concerned about health care reform, an issue where Clinton enjoyed a clear advantage. For these and possibly other reasons, disabled voters did not vote to support a president who has pushed very hard for their rights, harder than many Conservatives and Republicans would have liked.

Taylor tracked the presidential preferences of voters with disabilities at several points over the 1992 campaign, noting that Bush got a very significant bump with these voters after the Republican convention — he referenced the constituency and strong support for the Americans with Disabilities Act in his acceptance speech. But his bump quickly tanked over the following weeks as Clinton gained ground.
In 2004 available data indicates that voters with disabilities changed course. “People with disabilities have historically been much more likely to vote for the Democratic Presidential candidate with the exception of 2004 when they appeared to be more likely to vote for the Republican candidate, President George W. Bush,” according to the Kessler Foundation/National Organization on Disability 2010 report, “The ADA: 20 Years Later.”
In 2008, however, they cast 50 percent of their votes for Sen. Obama, vs. 44 percent for Sen. McCain, according to the final pre-election Harris Poll survey. The 2012 election should be an interesting test of this constituency’s preferences, considering the impact of HCR’s protection of people with disabilities from discrimination based on ‘prior condition’ by health insurance companies. They are also disproportionately impacted by budget cuts for health and social services, as well as unemployment.
Recent Harris Poll data indicates an impressive increase in turnout for voters with disabilities in presidential elections, with participation rates of 33 percent in 1996; 41 percent in 2000; 52 percent in 2004; and 59 percent in 2008, about the same as the general population for the first time. If this rising turnout trend continues among voters with disabilities — and their family members — it could provide an edge for President Obama and Dems in 2012.