MANASSAS, Va.--Standing on a stage together at a rally in this historic Civil War town, Mitt Romney clearly displayed chemistry with Paul Ryan -- whom he tapped to be his running mate on Saturday -- a risky pick by a man known for his caution.
The two teamed up against President Barack Obama, showing the punching power of the new Republican presidential ticket.
"Hope and change has become attack and blame," said Ryan, 42, speaking before Romney, 65, at an outdoor pavilion where the excitement among supporters was palpable.
They were flanked by their families -- and Ryan could have passed for one of Romney's five sons.
Ryan, the House Budget Committee chairman, is a native of Janesville, Wis., a conservative leader and a star rising so fast that Romney picked him over more prominent -- and safer choices -- such as Ohio Gov. Rob Portman or former Minnesota Gov. Tim Pawlenty.
By picking Ryan, the Romney campaign is making the election more about clear and vast differences on issues -- and less a referendum on Obama.
The choice of Ryan creates a target-rich environment for Democrats. At the same time, he energizes Republicans who have been suspicious of Romney's conservative credentials.
As a member of House GOP leadership, he will be portrayed as part of the radical right by Democrats.
Obama has been stepping up his attacks on Congress for wanting to protect Bush-era tax cuts for households with incomes over $250,000, and now that Ryan is the vice presidential candidate, the debate over tax cuts for the wealthy will be amplified.
Putting Ryan on the ticket brings to the front burner the future of Medicare, the federal health insurance program for seniors and some others.
Ryan, a deficit hawk and admirer of Ayn Rand, is the architect of proposals to turn Medicare into a voucher program -- users would buy private health insurance -- to curb escalating costs that threaten the viability of the popular program.
In Manassas, Romney said he will "restore, maintain and protect" Medicare -- with a more substantial marker to come later. Already on Saturday, Democrats seized on Medicare as a key line of attack against the newly minted ticket.
If there is one issue that animates and mobilizes Democrats -- it's Medicare. The Democratic Congressional Campaign Committee came out of the box with a hard jab at Ryan, calling him "the architect of the Republican plan to kill Medicare."
Ryan's reputation as a budget cutter -- his willingness to go after the social safety-net programs, his opposition to the Obama health-care law -- has made him a champion of the Tea Party movement.
The ticket gets it first Medicare test on Monday, when Romney stumps in Florida -- a key battleground state -- packed with seniors who turn out to vote.
Romney introduced Ryan with symbolic flourishes Saturday morning in Norfolk, standing in front the USS Wisconsin, a World War II battleship, with a musical fanfare -- from the "Air Force One" movie soundtrack -- titled "The Motorcade."
Romney recast a famous Chinese proverb -- the same one Adlai Stevenson once leaned on to praise Eleanor Roosevelt -- to express his admiration for Ryan: "He's never been content to simply curse the darkness," Romney said. "He'd rather light candles."
"Paul and I are beginning on a journey that will take us to every corner of America. We're offering a positive governing agenda that will lead to economic growth, to widespread and shared prosperity and that will improve the lives of our fellow citizens," Romney said.
A Romney campaign official said Romney decided on Ryan on Aug. 1, after he returned from his trip to England and Israel. The two create a historic Mormon/Catholic ticket.
Romney and Ryan will appear together at a "homecoming" rally on Sunday night in Waukesha, a suburb of Milwaukee that is in one of the most Republican counties in the nation. Under Wisconsin law, Ryan can also run to keep his House seat in the November election -- and a Romney campaign official said he will.
Wisconsin is also a battleground state. Republican National Committee Chairman Reince Priebus, who is from Wisconsin, once called it a "light blue state that can turn red under the right circumstances."
But the Milwaukee Journal Sentinel's Craig Gilbert said Ryan has never run statewide and he had limited "ability to change the outcome in his home state."
Vice President Joe Biden reached out to Ryan, the White House said, "to congratulate him on his selection and welcome him to the race." Biden told him "to enjoy the day with his family" and that "he looked forward to engaging him on the clear choice voters face this November."
One of Ryan's biggest resume gaps is one of Biden's greatest strengths: foreign policy. The vice presidential debate -- there is only one -- is Oct. 11.
Warming up the crowd here on this hot day in northern Virginia, Barbara Comstock, a Republican member of the Virginia House of Delegates, praised Ryan as a strong choice, saying: "Can you imagine how much they are freaking out in the White House and in Chicago?"
Or perhaps not.