Paul Ryan is no Sarah Palin. The importance of his ideas to the Republican presidential campaign is evidence of the growing stature of the US vice-presidency.
Ryan's entry into the US race reflects new vice-presidential role
Mitt Romney's choice of Wisconsin Congressman Paul Ryan as his vice-presidential running mate is a bold, risky move just before the Republican National Convention begins this month in Florida.
Mr Ryan is a leading conservative (and a Tea Party favourite) in the House of Representatives, and is renowned for his sometimes outspoken advocacy of fiscal and budgetary discipline. He is, most notably, the architect of a $5.3 trillion (Dh19.5 trillion) debt-cutting plan that would slash government spending - including Medicare, the national health insurance programme for Americans over 65.
Mr Romney will hope that his selection of Mr Ryan will energise a Republican campaign that, according to some polls, has been flagging of late. Mr Romney has clearly decided he needs to take a risk rather than selecting a "safer" (but less colourful) candidate such as Tim Pawlenty, a former Minnesota governor, or Rob Portman, a US senator from Ohio.
However, as in 2008, when Arizona Senator John McCain chose Sarah Palin as his Republican Party running mate, the selection of Mr Ryan presents something of a mixed bag for Mr Romney.
While the selection of Ms Palin was at first viewed as bold, the former Alaska governor became a liability. She was quickly viewed as too inexperienced to be president given her relatively light political resume.
By contrast, Mr Ryan has significant political experience after seven congressional terms, and is also of a different intellectual calibre than Ms Palin, especially in terms of policy.
The danger for Mr Romney is not that Mr Ryan will be branded a political lightweight. Rather, it is that Mr Ryan could prove intensely polarising and may turn off independents, and possibly some moderate Republicans.
Mr Romney may have decided to take the risk because he believes he needs to shake up the race and energise his conservative base, many of whom remain lukewarm about his personal brand of more moderate Republicanism. Campaigning with a younger candidate (Mr Ryan is 42, and Mr Romney is 65) might also spur supporters from their current slumber.
As in previous presidential election cycles, massive media attention has surrounded the selection of Mr Ryan. There are numerous reasons for this. Among the biggest: the vice presidency has become the single most common path to the office of the presidency.
Since 1960, four US vice presidents - Richard Nixon in 1960, Hubert Humphrey in 1968, Walter Mondale in 1984 and Al Gore in 2000 - won their respective party's presidential nomination but then lost the general election, while two vice presidents (Mr Nixon in 1968 and George HW Bush in 1988) were elected president. Lyndon Johnson and Gerald Ford became president after an assassination and a resignation, respectively.
One reason vice presidents enjoy success in securing their party's presidential nomination relates to the 22nd Amendment of the US Constitution. This amendment, ratified in 1951, restricts presidents from serving more than two four-year terms. Importantly for vice presidents, this allows for the possibility of organising a presidential campaign in the sitting president's second term without charges - from inside or outside the party - of disloyalty.
Should Mr Romney win in November, Mr Ryan could eventually become a relatively strong candidate for the Republican presidential nomination in 2020 or beyond. Moreover, if Mr Romney loses to President Barack Obama, but Mr Ryan distinguishes himself during the campaign, he could also be a leading Republican candidate at the next presidential election in 2016.
There is another, even more pragmatic, reason for the media interest in Mr Romney's selection: the office of the vice president has assumed more power in American administrations in recent years. This is reflected in recent decades in larger staff budgets, greater proximity to the centre of power through a West Wing office in the White House, weekly one-on-one meetings with the president, and authority to attend all presidential meetings.
As with some recent vice presidents, notably Al Gore and Dick Cheney, Mr Ryan could assume a very significant role in a Romney administration, especially on domestic policy, his forte.
It is for these reasons that attention will, sooner rather than later, zero in on Mr Ryan and his sometimes controversial record and beliefs - and most importantly, on his views on fiscal policy.
The Romney campaign's selection of Mr Ryan will prove a defining decision of the campaign. The Romney-Ryan ticket might secure invaluable momentum in the build up to the Republican National Convention. Or, if the decision proves a miscalculation, the wheels could come off. Either one will become clear soon enough.
Andrew Hammond is an associate partner at ReputationInc. He was formerly North America editor of Oxford Analytica