When Sen. Charles Schumer (D-N.Y.) dons sunglasses and bikes through the streets of Brooklyn on weekends, New York residents are oblivious to the predator in their midst. But they are not his prey.

Schumer, a 57-year-old with a receding hairline and a voracious appetite, is a political carnivore. In recent years, the senior senator from New York has instilled fear in Republicans; his gaze has fallen upon them and they know from the 2006 election cycle what that means.

When Schumer took over the Democratic Senatorial Campaign Committee (DSCC) after the 2004 elections, the Democratic Party was in disarray. Republicans had picked up seats in both chambers of Congress and retained the White House.

Schumer, a career politician, knew that the GOP had campaigned better that year. And unless Democrats stopped their electoral losing streak, Schumer feared Republicans would not only control Washington for years to come, but would dominate it.

In his recent book, Positively American: Winning Back the Middle-Class Majority One Family at a Time, Schumer wrote that he was excited to take over the DSCC because “I love campaigns and I don’t mind calling donors for money.”

That is an understatement. Schumer is an Olympian fundraiser. Despite being in the minority last cycle, the DSCC outraised the National Republican Senatorial Committee (NRSC). And not surprisingly, Schumer’s committee is thumping the NRSC in the money race this cycle.

Republicans won in 2004 because of their effective message, according to Schumer, which was: “War in Iraq. Cut taxes. No gay marriage.”

Schumer said Democrats won in 2006 with the message of “No war in Iraq. No corruption. Bad economy.”

The Hill interviewed Schumer and NRSC Chairman John Ensign (Nev.) this month. Ensign is a straight shooter who knows he has been dealt a bad hand. Retirements, the electoral map and the political winds have put Republicans in deep trouble.

Ensign stressed that he would not run the NRSC beyond the 2008 elections. By contrast, Schumer suggested he might stay on at the DSCC for what would be his third straight cycle. People tend to do what they want to do — and who doesn’t want to win?

One of the keys to the DSCC’s success over the past couple years is the relationship between Schumer and Majority Leader Harry Reid (D-Nev.). Schumer was not close with former Democratic Leader Tom Daschle (S.D.), but he is tight with Reid. As the New Yorker has noted, he and Reid “couldn’t be more different, yet … we are the best of friends.”

In all likelihood, Reid will be working with a bigger majority in the Senate next year. Schumer won’t predict that Democrats will get to the magic number of 60 seats, but he makes clear that his hit list is larger than it was in 2006. Republicans are taking notice, and taking cover.