Beginning what looks like a full-scale party offensive, Senate Democrats released a series of legislative proposals this week, which, they say, will serve as their Top 10 agenda items for the current session of Congress. There was a coherence to the enterprise that betrayed some of the policy strategizing and message-messaging that party leaders have been promising for some time. There was even a tag line with reasonable battle-cry potential: “Security, Opportunity, and Responsibility.” Acknowledging their disadvantage on national-security issues, the first three proposed bills deal with expanding troop strength, targeting terrorists, and increasing support for National Guard and Reserve units and for veterans. The rest is a lot of what you might expect from congressional Democrats: keeping jobs from going offshore and making health care more affordable; improving education, reducing the deficit, and increasing the minimum wage. “[O]pportunity, in America, is a fundamental value, and...