Washington — U.S. presidential candidates spend much of their campaigns discussing plans for entitlement programs like Social Security, Medicare and the American health system for a very important reason: U.S. seniors, who are most immediately affected by these types of government assistance, are paying close attention, and they are the most likely people to vote.

Analysis of past voter turnout has shown that in the United States, voting and registration rates have tended to increase with age. In the 2010 congressional election, 61 percent of those 65 and older voted, compared with only 21 percent of 18-to-24-year-olds.

Historically, older Americans have been more likely to vote Republican, and a majority of those 65 and older have backed the Republican candidate in the last two presidential elections. According to an analysis of the 2008 election, Republican nominee John McCain captured 53 percent of the elderly vote compared to President Obama’s 46 percent. In 2012, the critical swing states of Florida, Pennsylvania and Iowa each have significant senior populations.

According to the U.S. Census Bureau, in 2011 persons 65 or over constituted 13.3 percent of the U.S. population, or more than 41 million people. The median age of these U.S. senior citizens is 74, and 84 percent of them are retired. Due to advances in health care and longer life spans, the Census Bureau predicts that the U.S. senior population will more than double to 88.5 million by 2050, making up 20 percent of the population.

In the middle decades of the 20th century, the U.S. government set up social safety net programs like Social Security and Medicare, funded by American taxpayers, so seniors who left the workforce and became more likely to need health care would have a reliable income and support for their health costs. Many of today’s elderly, after paying into these programs throughout their careers, now depend upon them in addition to their personal retirement savings for their well-being.

The elderly share concerns with other Americans over the state of the U.S. economy, tax rates and the U.S. federal deficit. With many working-age Americans still looking for jobs and reliant on parents, those old enough to remember the hardships of the Great Depression recall the dangers of being in debt and large-scale financial insecurity.

In September, both President Obama and Republican vice presidential nominee Paul Ryan addressed a summit of the American Association of Retired Persons (AARP), one of the largest U.S. membership organizations and a powerful lobbying group in Washington.

Both referred to their late grandmothers in an effort to show their understanding of seniors’ concerns.

President Obama told the story of Madelyn Dunham, who had worked during World War II on a bomber assembly line “with a baby at home while her husband was off serving his country." He said that after working all of her life, “what she hoped for in return was to be able to live out her golden years with dignity and security, and to see her grandchildren and her great-grandchildren have a better life."

Obama said his grandmother did not want "help from me or anybody else. She just wanted to make sure that the work she had put in was going to pay off."

Ryan said that when he thought about the Medicare program, “I don't think about charts and graphs and numbers," but instead of “my wonderful grandma, Janet; she had Alzheimer's, and she moved in with my mom and me."

Though the disease affected her memory, “we did all those little things that made her feel loved. We had help from Medicare and it was there, just like it's there for my mom today," he said.

As President Obama and Republican challenger Mitt Romney continue to make their case to American voters, those most likely to show up at the polls will be listening carefully on how they plan to reduce the U.S. federal deficit while continuing to keep programs like Medicare and Social Security intact.