It's not just about winning states. Winning a presidential nomination includes mastering complex rules about delegates, and Pennsylvania's rules are among the most complicated.
The Republican took a detour from the campaign trail on Monday to try to build relationships with GOP officials — while also promoting his latest signature building just blocks from the White House.
Chelsi Henry, Will Estrada, Margaret Hoover and Eugene Spektor, four young Republicans, join NPR's Rachel Martin to talk about the state of the race, and Donald Trump's role in their party.
For all the attention Donald Trump has gotten, more people have voted for Hillary Clinton than any single candidate. Of course, Republicans have had a much bigger field — and record turnout.
Business leaders remember an economic boycott against the state for its 2010 immigration bill and worry about international consequences of a Trump presidency.
The 2012 GOP nominee says he's voting for the Texas senator in Tuesday's Utah GOP caucuses, hoping to force an open convention as a way of stopping Trump from getting the Republican nomination.