Four ways Hillary Clinton boxed out Joe Biden in Democratic debate

Aides called Hillary Clinton's Tuesday night debate performance the 'best day' of her campaign. Will her strong showing discourage Joe Biden from entering the race?

If Joe Biden was waiting for signs of weakness during Tuesday night's debate to spur him into the 2016 race, it was a long night for the vice president.

Not only was the first Democratic presidential debate substantive, lively, and well-articulated, Mr. Biden was not the dominating presence some expected. There were no 11th-hour declarations, no mention of the sixth podium, no morning-after announcement. In fact, over the course of the entire debate, about two full hours, no one even mentioned Biden.

Then there was Hillary Clinton's performance. As Biden considers a 2016 bid, the debate, and more specifically, Mrs. Clinton's conduct in it, has been viewed as an important factor in the vice president's final decision. The thinking: If, following months of bruising in the polls thanks to her e-mail scandal, Clinton was further weakened by a tough debate, Biden may be more inclined to step in.

But Clinton wasn't weakened. And she wasn't just unscathed. She was confident, polished, and relaxed, and according to most accounts, she emerged a stronger candidate than before.

Aides called it the "best day" of her campaign. And it might just have been the last day of Biden's deliberations.

How did Clinton box out Biden? Let us count the ways.

1. She aligned herself with the president

Throughout the debate, Clinton stuck close to the president, praising Obama's leadership (calling him a "great moral leader" on race relations), highlighting the issues on which they worked together (the Osama bin Laden raid decision), excusing his shortcomings (by blaming obstruction by Republicans), and minimizing their disagreements.

When she was questioned about her vote for the Iraq War, she masterfully turned the challenge into an almost-endorsement from Obama.

“He valued my judgment,” she said, shutting down questions by pointing out that Obama, who voted against the war, asked Clinton to be his secretary of state.

2. She co-opted Biden's campaign theme and potential coalition partners

Clinton effectively boxed out Biden by beating him to what would likely be his campaign theme: building on the work of the Obama administration, a natural extension for the vice president.

“There's a lot that I would like to do to build on the successes of President Obama,” Clinton said. ”But also, as I'm laying out, to go beyond.”

She also went out of her way to single out two of Biden's potential coalition partners and core supporters if he ran: African Americans and the LGBT community, two groups Biden has historically supported and done well with.

“For me, this is about bringing our country together again,” Clinton said during the debate. “And I will do everything I can to heal the divides: the divides economically, because there's too much inequality; the racial divides; the continuing discrimination against the LGBT community.”

3. She got help from Bernie Sanders on the e-mail controversy

Clinton's use of a private e-mail server while serving as secretary of state has long been viewed as a major weakness for Clinton, who's taken a battering in the polls because of it, and a major motivation for Biden, a sort of Democratic hedge, to enter the race.

But, in one of the night's biggest moments, Clinton's rival, Bernie Sanders, helped banish some of those concerns.

"Let me say – let me say something that may not be great politics. But I think the secretary is right, and that is that the American people are sick and tired of hearing about your damn e-mails," he said.

Clinton beamed ear-to-ear, gave Mr. Sanders a hearty handshake, and the crowd gave both candidates a standing ovation.

With the exception of Rhode Island governor Lincoln Chafee, who made a feeble attempt to question Clinton's credibility, it was the last time anyone mentioned Clinton's e-mails Tuesday night.

4. She took swings at her opponents

Clinton was so comfortable Tuesday night, she took swings at her opponents – and perhaps sent a warning shot to Biden and his camp.

While she largely left the lower-polling candidates untouched, she showed that she was unafraid to take on Sanders, whose surprise success has cut into her support.

Early in the debate, she went after Sanders aggressively on guns, one of the issues on which Sanders' position does not align with that of most liberals.

When Sanders was asked why he voted against the Brady Act, which mandated federal background checks on firearm purchases, and supported a federal bill that would have shielded gun shops from lawsuits, he said it was “a large and complicated bill,” with some provisions that he liked, and some he didn’t.

"It was pretty straightforward to me,” Clinton, who voted against the federal bill, snapped.

And when the Vermont senator praised the health care systems of Denmark and Norway, Clinton jumped at the opportunity. 

“I love Denmark,” she said, smirking. “We are not Denmark. We are the United States of America.”

Certainly, Clinton showed some weakness, on how she would crack down on Wall Street, or how she differs from Obama, for example. But if Biden was looking for a window of opportunity, Clinton did her best to slam it shut.