WHEN it came to selling the Great Society, President Lyndon Johnson did not hold back. In his telling he was offering a new republic, shriven of racial hatreds and purged of poverty, built by farsighted technocrats and legislators upon mountains of federal cash. As he signed one of several laws to create and fund a Department of Housing and Urban Development (HUD), Johnson called it “the Magna Carta to liberate our cities”. He promised model housing to replace slums, rent subsidies for the poor and loans to turn working men into homeowners. HUD’s work, declared LBJ, would “raise up a new America”.

The euphoria did not last long. Half a century on, the Great Society’s legacy is bitterly contested. The left shudders to imagine America without its welfare schemes and anti-discrimination rules. The right calls LBJ’s legacy a failed experiment in social engineering, trapping millions in listless dependency.

As a result, an interesting political test faces Julián Castro, a young Texan Democrat summoned this summer to Washington as HUD secretary, joining Barack Obama’s cabinet a few weeks before his 40th birthday. Mr Castro has been a label-defying prodigy since he was elected mayor of San Antonio, the second-most-populous city in Texas, in 2009. He is Hispanic, brought up by a single mother who was a fiery campaigner for Mexican-American rights. Yet Mr Castro is no radical. Giving the keynote address at the Democratic National Convention in 2012 (prompting comparisons with Barack Obama, who secured instant fame at the convention eight years earlier) he spoke of his immigrant grandmother who dropped out of school to support her family as a maid and cook, and taught herself to read and write. For Mr Castro, this was not a sob-story but a lesson about hard work and American opportunity. Texas is a place where people actually still have bootstraps, he told delegates, and—with a bit of help from society—“we expect folks to pull themselves up by them.”

He credits affirmative action with helping him and his identical twin brother Joaquín (since 2013 a member of Congress for San Antonio) to travel together from a city high school to Stanford University, then Harvard Law School. But ethnic labels do not easily capture him. He grew up speaking English (he began discreet Spanish lessons as mayor). Dapper and a bit prim, he could be a corporate lawyer. He urges Democrats not to take a monolithic Hispanic vote for granted. That is good advice and, from him, heartfelt. Many saw him running for governor of Texas in 2018, by which time some glibly asserted that a soaring Latino population would turn the state Democratic. Yet in November’s elections 44% of Texan Hispanic voters backed a Republican for governor: the state will be conservative for a while yet.

Mr Castro made his name in San Antonio by pulling off a progressive’s dream: persuading Hispanic and Anglo residents to back a new tax to finance pre-school classes for poor and immigrant four-year-olds. He built a coalition uniting low-income parents with business bosses, and held a referendum to secure an explicit mandate. To counter shrink-the-government types who grumbled about expensive “babysitting”, he promised to test the scheme’s outcomes, measuring pupils’ progress in future years.

His problem-solving style has caught the eye of Bill and Hillary Clinton. The couple invited the young Texan to dine at their home in Washington before his swearing-in as HUD secretary. That sparked headlines about a possible Clinton-Castro presidential ticket in 2016. Serving as a cabinet secretary will give Mr Castro national experience. And with 50m Hispanics in America, almost half of whom are eligible to vote, Latino stars are in demand (just ask such Republicans as Senator Marco Rubio of Florida). For all that, running a chunk of the Great Society carries risks, in an age when Washington is reviled and reformers call states and city halls the only places where interesting policies thrive. For almost 20 years Republican presidential candidates have growled about abolishing HUD. Conservatives call it an outdated backwater whose funds should be sent directly to the states, so that decisions are taken by politicians who live among regular folk, not Washington know-alls. Its budgets have been squeezed since the days of Ronald Reagan, who famously failed to recognise his own HUD secretary at a White House gathering, hailing him with a cheery-but-vague “Mr Mayor!”

Still a mayor at heart

Mr Castro seems to be trying something intriguing: treating HUD like a city hall, which (like the government of any metropolis) must impress voters with very different world-views and needs. On a recent two-day visit to Austin, Texas he was frank about HUD’s constraints. Every year, 10,000 public-housing units are lost to disrepair. Nowadays most restoration projects require private or charitable partners. But private buy-in is a positive sign, Mr Castro says. He sees the federal government as a “catalyst” and a “referee”, stepping in when some states fail those who need help. To secure broad consent for public investments, he wants HUD to measure outcomes better, for instance tracking high-school graduation rates of children in public housing. He enthuses about local innovations, telling a conference of city officials: “My business card may say HUD secretary, but I’m still a mayor at heart.”

As a national politician, Mr Castro is a work in progress. He can be oddly stiff. In Austin he toured a branch of a youth club active in tough inner-cities. “You’re in our Hall of Fame!” staff cried, noting that Mr Castro had used the club as a boy. “Thank y’all for the great work y’all do,” Mr Castro said earnestly. It was polite—but, oh, the tales Bill Clinton would have spun. Off-the-record he is candid, profane and shrewd, and should let more of that show. Still his data-driven, coalition-building instincts are timely: the national mood is too sour for LBJ swagger. While others yearn to tug his party far to the populist left, Mr Castro favours “aspirational, collaborative” politics. Democrats need more like him.