Scott Walker announces US Republican presidential run
- Published
Mr Walker is banking his reputation on his clashes with labour unions
Wisconsin Governor Scott Walker has announced he is seeking the Republican nomination for US president.
The 47-year-old tweeted, external "I'm in", joining a field of 14 others in his party competing for the 2016 election.
"I'm running for president to fight and win for the American people," he said in a video, external released on Monday.
He formally announced his run for US president at an afternoon event in Milwaukee.
The governor defeated a recall election and clashed with labour unions in his home state, and cut taxes by nearly $2bn (£1.3bn).
In addition to siding with business groups in Wisconsin, he has also legalised carrying concealed weapons, introduced further restrictions on abortions and made photo identification a requirement to vote.
In his announcement speech, Mr Walker promoted his legislative achievements as governor of Wisconsin including lowering taxes and passing voter ID and anti-abortion measures.
"If our reforms can work in a blue state like Wisconsin, they can work anywhere in America," Mr Walker said.
Analysis: Anthony Zurcher, BBC News
Mr Walker has joined the top tier of Republican candidates including Marco Rubio and Jeb Bush
Scott Walker enters the race for the Republican presidential nomination in an enviable position. For most of this year he's been the frontrunner in Iowa, which is the first state to vote in 2016. He's also among the leaders in New Hampshire, making him the only Republican candidate with a realistic chance of starting the primary season with back-to-back wins.
Mr Walker's appeal has been as a candidate who energises grass-roots conservative Tea Party activists while, as an incumbent governor of a moderate state, is still acceptable to the party's establishment.
The challenge for the Wisconsinite will be to continue to bridge that gap as the ideological components of his party are courted with more focused appeals by his competitors. If he can post strong results in solidly conservative Iowa and independent-minded New Hampshire, he'll have demonstrated that he can achieve such a feat - and could be well on his way to the nomination.
2016 runners and riders
Clockwise from top left: Rand Paul, Jeb Bush, Scott Walker, Marco Rubio, Bernie Sanders, Hillary Clinton
The early Republican frontrunner is Jeb Bush
Hillary Clinton will have learnt much from her failed campaign of 2008
Florida senator Marco Rubio lost some right-wing fans by backing a bipartisan immigration reform package
Wisconsin governor Scott Walker appeals to both the Republican establishment and the Tea Party
Libertarian Rand Paul has his supporters - and enemies - among Republicans
Veteran congressman Bernie Sanders is running as a Democrat despite never formally being part of the party