Analysis: The debate over the Democratic candidate – and the direction of the party – is just getting started

It wasn't all about Donald Trump.

At the opening Democratic debate Wednesday night, the 10 contenders on stage focused less on the Republican incumbent – after all, there was little disagreement there on the threat they said he posed to the republic — and more on the direction of the Democratic Party.

On that there was a real debate – one that's just getting started.

Massachusetts Sen. Elizabeth Warren called for abolishing private health insurance coverage in favor of a government-run system. "I'm with Bernie (Sanders) on Medicare for All," she declared, a friendly reference to her biggest rival to lead the party's most liberal voters. Minnesota Sen. Amy Klobuchar cautioned that she was "concerned about kicking half of America off their health insurance in four years."

When former Texas congressman Beto O'Rourke said he would keep private coverage as an option, New York Mayor Bill de Blasio demanded almost angrily, "How can you defend a system that's not working?"

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The two-hour debate spotlighted differences over how far left the Democratic Party should move, though it clearly has moved left on some economic and other issues since the last election, and what voters it should target. That divide is likely to be in even sharper relief Thursday night. The second-day debate will feature another 10 contenders, including former vice president Joe Biden standing side-by-side with Sanders on the Miami stage.

That would be "Uncle Joe" from Scranton, Pennsylvania, and the Vermont senator who proudly calls himself a democratic socialist. Biden has led national polls of the Democratic contenders, and Sanders generally has been second.

At Wednesday's forum, hosted by NBC, MSNBC and Telemundo, the candidates avoided the name-calling and derisive nicknames that Trump used four years ago to dominate the Republican primaries. That contest also included a field of candidates so large that their early debates had to be held over two nights. 

Who are they?:Meet the people running for president in 2020

That said, former Housing Secretary Julian Castro went after his fellow Texan, O'Rourke, over their differences on immigration. Castro, suggesting O'Rourke didn't "do your homework on this issue," began a back-and-forth exchange that reflected long-standing grievances between the two on the topic.

Rep. Tulsi Gabbard of Hawaii and Ohio Rep. Tim Ryan clashed with some heat on U.S. involvement in Afghanistan.

Klobuchar slapped down Washington Gov. Jay Inslee after he bragged that he was the only candidate who had "passed a law protecting a woman's right of reproductive health."

"I just want to say there are three women up here who have fought pretty hard for a woman's right to choose," she said dryly. 

The imperative to deny President Trump a second term was nearly religious in its intensity. Asked to name the biggest geopolitical threat facing the USA, Inslee replied to scattered applause: Donald Trump. (Trump, aboard Air Force One on his way to the G-20 summit in Japan, tweeted a one-word review of the debate: "BORING.")

How best to achieve Trump's downfall was the subject of a sectarian divide.

Appeal to liberal voters, especially younger ones, with a promise of free college tuition, which Warren backed? Or target more moderate working-class voters from places such as Pennsylvania, Michigan and Wisconsin who helped put Trump in the White House?

"We are not connecting to the working-class people in the very states I represent, in Ohio, in the industrial Midwest," Ryan said. "We've lost all connection. We've got to change the center of gravity of the Democratic Party from being coastal, elitist and Ivy League, which is the perception to someone from the forgotten communities that have been left behind for the last 30 years."

The candidates, many of them not particularly well-known nationally, tried to tell viewers a bit about their personal stories. Warren noted that she grew up in Oklahoma. De Blasio mentioned that he was raising an African American son, Dante. Gabbard talked about her service in the Iraq War as a member of the Hawaii Army National Guard. Klobuchar said she weighed proposals on gun control by asking herself, "Does this hurt my Uncle Dick in his deer stand?" 

First O'Rourke, then New Jersey Sen. Cory Booker, then Castro launched into Spanish in an answer or two, a not-so-subtle appeal to Hispanic voters.

Closing comments:`We can't return to the same old approach,' and other lines from the Democratic debate

None of the contenders clearly dominated the evening, and no one made the sort of cringe-worthy misstep that could undermine their campaign. O'Rourke sometimes seemed to struggle to get into the conversation. Warren's command of policy details projected strength in the first half of the evening, although she faded a bit in the second half. At that point, Booker came across as confident and passionate; scorekeepers said he ended up with the most talking-time, a little more than 11 minutes.  

When journalist Dan Rather tweeted afterward, "One last thought, how many people think Julian Castro had a good night?" there was a quick response: "Me," Julian Castro replied.