Scott Walker: A little-known 2016 frontrunner

The governor jetted off to London this week to meet Prime Minister David Cameron and give a speech on global economics at Chatham House riding a wave of good publicity, encouraging polls and positive chatter among conservative talking heads.

Last week a Bloomberg-Des Moines Register survey of Iowa Republicans revealed that Mr Walker had surged to the top among those rumoured to be interested in their party's presidential nomination. The opinion of Iowans is particularly important, as their state will be the first to hold caucuses next year to determine the nominee.

The results were far from decisive - Mr Walker garnered 15%, compared with Senator Rand Paul's 14% and former Arkansas Governor Mike Huckabee at 10%. In New Hampshire, which holds its primary a week after Iowa votes, a new poll puts Mr Walker in third, a few percentage points behind Mr Paul and former Florida Governor Jeb Bush.

Coming on the heels of a well-received speech to party faithful at anIowa event in January that included more than a dozen possible candidates, however, it was more than enough to send the Walker hype balloon skyward.

Rush Limbaugh, a conservative kingmaker of sorts, has made trumpeting Mr Walker a veritable pastime recently. In the past two weeks, according to a tally by the National Journal, the conservative radio host has mentioned the governor's name more than 200 times.

The fortunes of presidential aspirants rise and fall, of course, particularly this early in the process. Four years ago the fickle tastes of Republican voters boosted and then dashed the hopes of a grab-bag of previously obscure candidates. Behind Mr Walker's recent surge, however, is a substance that could give him electoral staying power.

Scott Walker leaves 10 Downing street after meeting Prime Minster David Cameron

First and foremost, primary voters - across the political spectrum - love governors. As the titular head of their states, they wield executive power that allows them to take firm stands and avoid the often muddled voting records compiled by legislators in the US Congress.

Mr Walker, in particular, has been particularly authoritative in office, as he moved quickly to advance a distinctly conservative agenda after being elected in 2010. He became a favourite of grass-root Tea Party conservatives and anathema to his state's progressives for pushing to curtail the collective bargaining rights of teachers' unions and state employees, enacting new voter identification laws and cutting public funding for Planned Parenthood.

"Walker has made a short career out of defeating Democrats, despite pushing polarising policies that should alarm middle and working-class voters," writes Keith Brekhus of the liberal website PoliticusUSA. "He is one candidate Democrats cannot afford to underestimate."

The anti-Walker sentiment among the left was so fierce that it gave birth to a 2012 recall effort to remove the governor from office before the end of his four-year term. A statewide vote retained Mr Walker, 53% to 36%, however. The governor then went on to win re-election to a second term last November by a slightly smaller margin, despite running against a well-funded, popular Democratic opponent.