Any major natural disaster in any country strengthens the hands of political parties that advocate increased government funding for survivors and increased government commitment to try to prevent the disasters recurring. The classic example in U.S. history was the Dust Bowl in the first half of the 1930s, which forced hundreds of thousands of people in heartland states, especially Oklahoma, to head west.

Most of the refugees from the ravaged farmlands ended up in California. But the overall result of the disaster was to greatly boost the powers and credibility of the federal government and its commitment to practices dedicated to preventing land erosion.

The likely consequence of the current flooding in Iowa and the busting of levees on the Mississippi River will be to force a renewed government commitment to maintain the existing levees and greatly strengthen them. This will be the case especially as the pressures of global climate change will generate concern that more and similar floods will follow.

Also, the U.S. federal government has been committed to preventing catastrophic flooding on heartland rivers, especially the Mississippi, since the days of President Calvin Coolidge more than 80 years ago. Coolidge, now regarded as one of the most minimalist and non-interventionist of modern presidents in his philosophy of government, made that commitment after catastrophic floods in southern Illinois in April 1927 cost hundreds of lives. Coolidge resisted a generous and wide-ranging federal financial relief program but the following year was forced to sign one tending in that direction anyway.

The death toll in the 1927 floods -- caused by a 1,200-foot-wide levee collapse -- was vastly higher than anything we have seen so far in the current crisis. The failure of President Bush and his GOP congressional allies to adequately maintain the levees around New Orleans before Hurricane Katrina hit was therefore a failure to ensure a major responsibility of the federal government that preceded the New Deal by almost six years and that had been undertaken by a GOP president who in recent decades has become a conservative icon.

But the Iowa floods genuinely have been unprecedented. According to some assessments, they are the worst in the region in 500 years. They offer a concrete example of the impact of global change on the American heartland.

When people suffer unprecedented disaster personally from climate change, they tend to take it a lot more seriously than they did before: And they tend to drop their conspiracy theories about the Federal Emergency Management Agency being an agent of communism, the devil, or -- even worse -- President Bill Clinton -- views that were widely expressed during the secure peace and prosperity years of the 1990s.

The political impact of the floods and the threats to the levees, therefore, are very likely to make millions of independent voters and formerly GOP-supporting Americans far more focused on spending federal money on levee maintenance and repair and on disaster relief programs, even if FEMA is the agency administering them.

And they are also likely to give far more credibility to the prophets warning of the impact global climate change is going to have on the United States.

McCain, R-Ariz., is better prepared to deal with these issues than any other possible Republican presidential candidate this year. But the issues still skew overwhelmingly to the advantage of the Democrats and Obama, D-Ill, the Democratic presidential standard-bearer.

Therefore, look for Obama to pick up more votes across the Midwest and the lower Mississippi from the emerging debate over the current crisis. The Democratic philosophy of interventionist government is likely to resonate more strongly with voters in the afflicted regions than the Republican one of minimal government and self-help.