Because of state-by-state winner-take-all laws, not mentioned, much less endorsed, in the Constitution. . .
Since World War II, a shift of a few thousand votes in one, two, or three states would have elected the second-place candidate in 4 of the 16 presidential elections
Policies important to the citizens of non-battleground states are not as highly prioritized as policies important to ‘battleground’ states when it comes to governing.
“Battleground” states receive 7% more presidentially controlled grants than “spectator” states, twice as many presidential disaster declarations, more Superfund enforcement exemptions, and more No Child Left Behind law exemptions.
Compare the response to hurricane Katrina (in Louisiana, a “safe” state) to the federal response to hurricanes in Florida (a “swing” state) under Presidents of both parties. President Obama took more interest in the BP oil spill, once it reached Florida’s shores, after it had first reached Louisiana. Some pandering policy examples include ethanol subsidies, steel tariffs, and Medicare Part D. Policies not given priority, include those most important to non-battleground states — like water issues in the west.
The interests of battleground states shape innumerable government policies, including, for example, steel quotas imposed by the free-trade president, George W. Bush, from the free-trade party.
Parochial local considerations of battleground states preoccupy presidential candidates as well as sitting Presidents (contemplating their own reelection or the ascension of their preferred successor).
Even travel by sitting Presidents and Cabinet members in non-election years is skewed to battleground states