Cruz’s rise is partly the result of methodical campaign planning, but also sheer luck.

The surprise appeal of Donald Trump and Ben Carson has redefined ideas about who is considered a political outsider. Billionaire Trump’s bombastic style and sometimes offensive campaign has left Cruz looking more presidential. And compared to Carson, the first-term senator seems experienced. If those front-runners eventually fade, as some expect they will, Cruz is poised to scoop up their large base of anti-establishment supporters…

The Harvard-trained lawyer has shunned his party’s conventional campaign wisdom, much the way Obama did, ignoring calls to be mindful of the political center that eventually will be needed to capture a broader segment of independent and moderate votes. Instead, Cruz believes the race for the White House will be won by building a conservative grass-roots political movement, tapping into voters hungering for a candidate who will animate the base and unleash enthusiasm. He has studied the playbook of former Obama campaign strategist David Plouffe. His performance could provide a test of the polarization of the American electorate.

“He’s quietly working through the grass roots … like a marathon runner,” said Chris Winn, the Lubbock county treasurer who has long worked on Republican campaigns. “We need to be the cowboy again. … It does come down to almost a crusade, and Cruz has the clarion call to the nation that this is a good-versus-evil moment.”