Newsletter: Essential Politics: GOP presidential contest grows more intense

With Wednesday's debate among the GOP hopefuls, the presidential campaign opened a new, more intense phase in which candidates increasingly will be on the attack.

As Michael A. Memoli and Mark Z. Barabak described in their account of the debate, the latest session featured an effort by Jeb Bush to attack his one-time protégé, Sen. Marco Rubio. In the duel between the two Floridians, Rubio came out on top, as Michael Finnegan explained.

The result: consternation in the Bush camp as Seema Mehta, Noah Bierman and I reported, and increasing questions about whether the one-time front-runner can fix what ails his campaign.

Good afternoon, I'm David Lauter, Washington bureau chief. Welcome to the Friday afternoon edition of Essential Politics, in which we review the week's developments in the presidential campaign and highlight some of the stories that provide insight behind the headline news.

The debates continue to draw high ratings, as Stephen Battaglio reported. In a story earlier this week, Barabak explored how and why debates became must-watch TV.

As Cathleen Decker pointed out in her analysis of the most recent GOP debate, the contests in the two parties are moving in opposite directions. (And if you prefer to hear the analysis, rather than read it, check out this video of Decker and Mehta discussing the contest.)

The Democratic field has narrowed, with Vice President Joe Biden passing up the race while Jim Webb and Lincoln Chafee dropped out. The Republican contest, by contrast, has broadened, with more candidates moving into the viable middle range behind the two leaders, Donald Trump and Ben Carson.

One way to think about the GOP race is in terms of separate lanes. In one lane, Trump and Carson compete for voters who are fed up with traditional politicians and elected officials. In another, Bush, Rubio and Ohio Gov. John Kasich vie for the support of more establishment-oriented Republicans voters, the sort who ultimately delivered the nomination in 2012 to Mitt Romney.

Sen. Ted Cruz of Texas has positioned himself in a third lane, appealing to tea party conservatives who don't think that Trump or Carson are viable nominees.

Cruz is not directly taking on the two leaders, but even before the debate, doubts about Trump had been growing among Republican voters. If those doubts grow, Cruz hopes to be the beneficiary. Potentially, Sen. Rand Paul and former Arkansas Gov. Mike Huckabee could compete with Cruz for those voters, but their campaigns have both struggled.

Both Cruz and Paul went to the Senate floor to oppose the budget deal that Republican leaders negotiated with the White House. As Lisa Mascaro explains, the deal isn't the sort of blockbuster "grand bargain" that former House Speaker John A. Boehner once tried to negotiate, but it still will affect the lives of millions of Americans.

Finally, one issue that could emerge as critical in primaries in western states is the perennial conflict over federal lands. William Yardley explores the issue and its political implications.

That wraps up this week. On Monday, my colleague Christina Bellantoni will be back with the daily newsletter. Until then, keep track of all the developments in the 2016 campaign with our Trail Guide, at our politics page and on Twitter at @latimespolitics.

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