As analysts review the results of the 2010 midterm elections, one trend becomes strikingly clear: Older voters have turned against the Democratic Party. 

Without the votes of Americans over 65 — who preferred the GOP by 21 points in 2010, compared with an even split four years ago — Republicans would have gained far fewer seats in Congress.

In the 2008 presidential election, Americans over 65 had already begun to move away from Democrats, giving Sen. John McCain (R-Ariz.) an 8 percent advantage over President Barack Obama.

The question now is whether the huge shift to Republicans represent a temporary or a permanent realignment of this all-important senior voting bloc — and whether it will affect the upcoming 2012 presidential election. The answer may well come soon in the way in which Democrats and Republicans deal with senior’s biggest concern: Medicare.

This issue matters to older voters for a simple reason: All Americans over 65 rely on the Medicare program in some way, and around 85 percent of them have a chronic condition that requires ongoing care. During the recent elections, seniors expressed a real fear of losing Medicare benefits at a time when their health may worsen, and Democrats paid the price for doing little to allay these fears.

Republicans, on the other hand, have a pretty good record on Medicare: A Republican Congress and Republican president, after all, engineered the most recent sizeable expansion in the program, the prescription drug benefit known as Medicare Part D, and fought the deep cuts in the program that Obama pushed through Congress earlier this year as part of his health care overhaul.

For Democrats, the equation is simple but difficult. Can Democrats recapture the 65-plus senior vote in the face of seniors’ grave concerns over last year’s Medicare cuts by becoming the great defenders of seniors’ access to Medicare services? The Obama administration may have just made that job even harder when, on Election Day, the Centers for Medicare and Medicaid Services announced new deep cuts in one of seniors’ most popular and critical services: home health care.

Estimates are that these cuts will likely result in as many as 35 percent of America’s home health agencies going out of business, possibly denying senior access to these important services, sending them into more expensive hospital and nursing home settings. Incredibly, CMS ordered these new cuts on top of the nearly $40 billion in home health care contained in the health reform bill, despite the Senate’s unanimous resolution against further cuts.

Seniors are livid.

For Republicans, the equation is equally simple, but much more doable. Can they solidify their huge 21 percent senior vote gain by opposing these Medicare cuts, especially the announced and soon-to-be-considered additional cuts to home health? Or will they miss this great opportunity by failing to be seen as the great defenders of senior health care services? For Republicans interested in restraining federal spending, defending home health for seniors is a no-brainer.

A typical week in a hospital costs about $43,000; a week in a nursing home comes in at $1,500. By comparison, a visit from a home health care aide costs significantly less. A recent Lewin Group report confirms these big savings when home health is used. Keeping seniors healthy in their own homes is not just good politics; it’s good Republican economics.

Locking down the 65-plus senior vote for future elections is a great opportunity for Republicans. Losing that critical voting bloc represents a real danger for Democrats. Opportunity and danger:  two central elements of a crisis. Will Republicans seize the opportunity, or will Democrats recognize the danger in time? Such is the political drama of a good Washington-style “crisis.”

Former Rep. Billy Tauzin (R-La.) served as chairman of the Energy and Commerce Committee from 2001 to 2004. He is president and CEO of Tauzin Strategic Networks, a lobbying group that represents health care clients including those in the home health care sector.