WASHINGTON — Paul Davis Ryan, a son and grandson of Midwestern lawyers, ascended rapidly in American politics as a man with big plans: overhauling the tax code, slashing federal spending and rewriting the social contracts for Medicare and Social Security.  Now, as he grips the gavel as the youngest speaker of the House since the late 1860s — a time when his ancestors were already settled in Wisconsin — Mr. Ryan, 45, confronts a fundamental question: Will his new post provide a platform to pursue his bold visions for a renewed America, or will those big ideas ultimately weigh him down in an era defined by confrontation and small-bore compromise?  Recent experience, including the success of President Obama and congressional Democrats in blocking all of Mr. Ryan’s big budget proposals, suggests that he will continue to harbor expansive aspirations, but will set more modest goals.  He faces not merely the realities of divided government, at least for the next 14 months; he also will try to repair the deep fractures among House Republicans. Mr. Ryan acknowledged as much in his opening remarks when he declared, “The House is broken.”  Representative Paul D. Ryan of Wisconsin accepted his new position as House speaker on Wednesday, replacing John A. Boehner of Ohio.  It was Mr. Ryan who negotiated for Republicans in reaching a crucial budget accord after a damaging government shutdown in 2013, curtailing expectations but ultimately clinching a deal that he noted “was small in substance but big in symbolism.”  “We spoke of having to scale back our ambitions,” Mr. Ryan wrote of his negotiations with Senator Patty Murray, Democrat of Washington, “from trying to score a touchdown, to getting a first down, to just getting positive yardage.”  “When we tried to go big, we realized we were on different teams with different end zones,” Mr. Ryan, a lifelong Green Bay Packers fan, wrote, continuing the football metaphor in his 2014 book, “The Way Forward.” “But there was in fact common ground.”  By his own account, Mr. Ryan, who was elected to the House in 1998 at age 28 and was tapped by Mitt Romney as the Republican Party’s vice-presidential nominee in 2012, is a somewhat accidental traveler in the corridors of power, one whose passion lies in the grinding details of policy prescriptions and budget scores.  His policy work, however, has also created a clear public record allowing Democrats to frame their disagreements with him, especially on his budget proposals, which have included transforming Medicare into a voucher program; partially privatizing Social Security; and abolishing the corporate income tax, the estate tax and the Alternative Minimum Tax.  The House Democratic leader, Nancy Pelosi of California, said in an interview that she looked forward to working with Mr. Ryan and would “extend a hand of friendship” but also expected a fierce debate over priorities.  “This presents this clearest distinction of anyone they could have named: the Ryan Budget,” Ms. Pelosi said. “Eight-hundred-billion-dollar cuts in Medicare; big tax breaks to the wealthiest people; voucherizing Medicare, not giving a guarantee; block-granting Medicaid, which 65 to 70 percent goes to seniors for long-term health care.”  “A budget is supposed to be a statement of values about our county,” Ms. Pelosi added. “So it will be interesting to see if now, in the position of speaker, if those will still be his priorities, and if so, we welcome the debate on the substance.”  Ms. Pelosi said that she hoped Mr. Ryan would be inspired by his desire to spend time with his children to pursue legislation that would grant paid leave to American workers for child care, and provide other benefits for middle-class families.  “I hope that he would translate his personal values into public policy to enable people to have paid leave if their child is sick,” she said.  For better or worse, current and former colleagues say, Mr. Ryan, a father of three young children who live with his wife in Janesville, Wis., sincerely believes in the policy proposals that he puts forward, and more importantly in the social values those proposals are rooted in.  A devout Catholic and former altar boy, Mr. Ryan has written and spoken extensively about his belief that private, voluntary charity can do a better job than government in helping the poor and other needy Americans.  Mr. Ryan’s ideas are not just about the dollars and cents of taxes and spending. He has expressed a willingness to work with Democrats on immigration issues that some of his more conservative colleagues find troubling.  And in his book, he lays out a vision for overhauling antipoverty and other social welfare programs that at times seems to blend elements of Lyndon B. Johnson’s “Great Society” with the conservative-libertarian philosophies and market-based approaches of Jack F. Kemp, the longtime New York representative who was a hero and mentor to Mr. Ryan.  “Today, there are at least 92 federal programs that claim to help the poor,” Mr. Ryan wrote. We spent $799 billion on them in 2012 alone. And yet, the official poverty rate is the highest it has been in 21 years.”  Some Democrats complain that Mr. Ryan is big on talking points but ultimately falls back on a different approach favored by Mr. Kemp: the trickle-down economics of the Reagan era that they say will help neither the poor nor the middle class.  And some colleagues say that when Mr. Ryan was afforded his best chance to potentially advance sweeping fiscal reforms — as a member in 2010 of the National Commission on Fiscal Responsibility and Reform, a bipartisan panel — he ultimately chose partisan politics and Republican unity over a potentially far-reaching compromise.  “We had an opportunity,” former Senator Kent Conrad, Democrat of North Dakota, who served with him on the panel, said in a recent interview. “We would have fixed Social Security. We would have fixed the long-term imbalances the country is facing. We would have improved Medicare. It would have put America a position to have a resurgence. It would have put confidence in our institutions.”  Mr. Conrad added, “Paul really, I think, failed that test.”  To a large degree, the budget accord reached this week, which Mr. Ryan voted to support, will free him from any immediate need to pursue his most ambitious fiscal proposals, and should clear some room for him to focus on some of the nuts-and-bolts complaints about how the House operates that have divided Republicans.  A substantial portion of Mr. Ryan’s remarks on Thursday were addressed to these conservatives, including members of the hard-line House Freedom Caucus, who have demanded changes in House rules to empower individual members and weaken the leadership.  While Mr. Ryan is an advocate of growing a bigger tent for the Republican Party, it is unclear that he will be able to do much toward that goal given the likelihood of continuing pressure from the right-wing of the House Republican conference, which has expressed a strong preference for ideological purity and a distaste for compromise.  Mr. Ryan, in his speech, called for a more conciliatory approach. “We have nothing to fear from honest differences, honestly stated,” he told his colleagues. “If you have ideas, let’s hear them. I believe a greater clarity between us can lead to a greater charity among us.”  “I believe, with every fiber of my being, we can renew the America Idea,” he said later, adding: “Let’s seize the moment. Let’s rise to the occasion.”
Mr. Ryan rocketed to political stardom with big plans, but he is likely to settle on modest goals as he seeks to repair the deep fractures in the House Republican caucus.