Republican presidential candidate Mitt Romney has introduced Wisconsin congressman Paul Ryan as his running mate, choosing a politician who is viewed as a bridge between the Republican establishment that backs Mr Romney and the small-tax, anti-big government Tea Party movement that distrusts him.
Mr Ryan is the architect of a deeply conservative and intensely controversial long-term budget plan to cut trillions in federal spending, and his conservative credentials are highly regarded by fellow Republican House members.
Many polls during the primaries of winter and spring found that Mr Romney's own credentials were suspect among the party's core, Tea Party supporters.
With his pick, Mr Romney sought to boost his own image among the conservatives, repair an image damaged by negative Democratic advertising and shift the trajectory of a campaign that has seen him lose ground to president Barack Obama.
Mr Ryan came out swinging, blaming the president for the country's sluggish economy. "Regrettably, President Obama has become part of the problem, and Mitt Romney is the solution" to an economy that has yet to make a strong recovery from the worst recession in decades, he said.
Mr Romney exulted in his choice, telling cheering supporters gathered before them that "I did not make a mistake with this guy".
In the campaign to come, Republicans will present economic solutions "that are bold, specific and achievable", Mr Romney said. "We offer our commitment to create 12 million new jobs and bring better take-home pay to middle class families."
The ticket-mates made their first joint appearance at a naval museum, the initial stop of a bus tour through four battleground states in as many days.
Having Mr Ryan on the ticket could also help Mr Romney become more competitive in Wisconsin, a state Mr Obama won handily four years ago in the state-by-state race for the presidency, but that could be much tighter this November. At same time, Democrats have been eager for Mr Romney to choose Mr Ryan, so they could pin what they see as an unpopular budget plan that calls for deep cuts in government spending and overhaul entitlement programmes to the Romney campaign.
At 42, Mr Ryan is a generation younger than the 65-year-old Mr Romney. A seventh-term congressman, Mr Ryan is chairman of the House Budget Committee, and primary author of conservative tax and spending blueprints that the Tea Party-infused Republican majority approved over vociferous Democratic opposition in 2011 and again in 2012.