From the Washington Post
Big states — by population — simply matter more for a variety of reasons but, most notably, because of their role in the decennial Congressional line-drawing process known as redistricting.
Every ten years, a handful of states gain or lose seats based on population rises and declines — a process that hands power to create or destroy careers typically in the hands of a governor and a small group of state legislators.
Big states are typically the, um, biggest, winners and losers from this process and 2011 looks no different with places like Texas and Florida poised to gain seats and Michigan and Oho likely to lose them.
Democrats would gladly cede their seats in Wyoming, Kansas, and Oklahoma if it means they can steal Florida or Texas from Republicans. The ability to move around the 10 combined Congressional districts in those small states is exponentially less appealing than being able to shape the 32 in Texas or the 25 in Florida.