What it says is that Senator Harry Reid, working with organized labor and through a variety of groups, and with the latest technology, has built a Democratic ground operation that is the envy of the political world--including Republicans, who make clear that Reid and the Democrats have done an excellent job at this. And that this ground game may help Barack Obama overcome Mitt Romney in Nevada, and could help Shelley Berkley past Dean Heller. It also points out that Reid acted in part out of "self-preservation": his close-as-close-can-be victory over John Ensign in 1998 for reelection and the Republican dominance demonstrated in the elections afterward.
What it doesn't say is striking. That is, the use of the word "machine." Terminology changes in politics. Consider that those now called "liberal" were really moderate not long ago, and those now called "conservative" really are well to the right of where you would have found most conservatives as recently as the 1980s. A machine used to be a highly corrupt operation, usually run by one person who didn't hold office or held a local office, to keep the graft coming in. That's hardly what The Times meant by "Reid's machine," or what that machine actually does or tries to do.
Comparisons might be in order. During the first third of the 20th century, mining/banking/hotel magnate George Wingfield had what was called a "bipartisan machine" that supported candidates of either party, so long as those candidates toed the Wingfield line of federal help for Nevada and limited government otherwise. The next machine belonged to Pat McCarran, who wanted to dominate Nevadans in Washington and Democrats back home, although he was willing to rule the world if given the chance. Certainly, Reid benefits from the success of Nevada's Democratic party, and he and party leaders have involved themselves in some primaries to keep the peace. But the word machine has a slightly different connotation in this case.
Further, it's funny to think of Reid dominating the Democratic party. If he's in storytelling mode, it's a different matter. Earlier this year, friends honored longtime Democratic activist Harriet Trudell, and Reid had everybody laughing at stories of how he always had big plans to run the state party, and Trudell would take care of that. Or as another longtime friend of Reid's once put it, a lot of powerful people can get together and make decisions, but until the voter pulls the lever or pushes the button, it really doesn't matter.