Possible Clues:

• World capital laid out in the late 1950s
• Supporter on top of inert stuff that's less Conservative, reaching a capital city
• Blair's going out on first-class return to acquire foreign capital
• City of Brazil
• Portuguese-speaking capital
• Intimate clothing troubles holding one back in capital
• Capital in trouble is suffering setback after initial support
• Supporter trouble is on the rise for City
• Capital of the largest South American country
• S. American capital