In my column for CNN I explain how putting Paul Ryan on Mitt Romney's presidential ticket will allow Barack Obama to define the terms of this election:
In a classic "Saturday Night Live" sketch, Christopher Walken plays a music producer with just one message for his bands: "More cowbell! I gotta have more cowbell!"
Sometimes you wonder if Walken is producing this year's election, too. In Mitt Romney, the GOP has nominated its least ideological candidate since Richard Nixon. At every turn, the party has demanded, "More ideology! I gotta have more ideology!" With the selection of Paul Ryan as his running mate, Romney has now acceded to that wish. The least ideological Republican candidate since 1968 has committed himself to the most ideological Republican program since 1964.
Democrats must be stunned.
The first battle in every election is the battle to decide what the election is about. What's the question voters must answer?
In 1992, for example, Republicans wanted the election to be about George H.W. Bush's steady leadership in a dangerous world: the end of the Cold War and victory in the Persian Gulf. Democrats countered, "It's the economy, stupid!"
This year, an incumbent even more embattled than George H.W. Bush has his own preferred election theme. He doesn't want to debate his own record, which is pretty dismal. He wants to debate the record of the congressional Republicans elected in 2010, a bunch radically less popular even than the president himself.
You'd imagine that Romney's job was to refuse the Democratic invitation, to choose his own ground for the election, and to keep his distance from the congressional GOP. You'd imagine, but you'd be wrong.
Romney has instead chosen to bolt himself to the House Republicans. He has chosen as his running mate Paul Ryan, the House Republican leader -- not their formal leader, but their intellectual leader, the person who set their agenda. He has effectively adopted Paul Ryan's agenda as his own: big immediate cuts in spending, a dramatic cut in the top rate of income tax to 28% and a bold reform of Medicare for those 55 and under.
Obama's message in 2012: "Forget the economy. It's Medicare, stupid!"
The Romney-Ryan response? "We agree. Medicare it is."