– Welcome to the top, Elizabeth Warren.

That was a central message of the presidential Democratic debate Tuesday, when the Massachusetts senator’s rivals peppered her with hostile questions and blunt challenges to her policies on health care, taxes and more.

The debate was the first to be held since Warren moved into the lead of many national and early-state polls, challenging Joe Biden’s status as front-runner, and she drew fire that she had largely escaped in earlier rounds.

The spotlight illuminated both her strengths and vulnerabilities: Her responses showcased the intellectual prowess that has helped fuel her rise, but also featured the ideological edge and sometimes condescending tone that critics fear could alienate swing voters.

Sen. Amy Klobuchar of Minnesota, who clashed several times with Warren, called her out early on for seeming to suggest that Democrats who don’t agree with her ideas don’t care about the middle class.

“I think simply because you have different ideas doesn’t mean you’re [not] fighting for regular people,” said Klobuchar, who joined others in saying that Warren’s ambitious policy plans were unrealistic.

The pushback against Warren came amid a debate that amounted to a stress test for the top-tier candidates in a race that has changed markedly since the last time they met for a debate, in mid-September.

For Sen. Bernie Sanders, the debate was a test of his stamina following a heart attack two weeks ago; he held up with a robust performance.

For Joe Biden, it was a test of how he was weathering a barrage of attacks from President Donald Trump; he brushed off a moderator’s question, and his rivals largely avoided going after the former vice president.

Instead, while the debate featured many examples of candidates lunging and parrying with each other, no one sustained as many challenges as Warren.

The nature of the debate testified to how much Warren’s position has improved in recent months. Biden has remained at the top of most polls but his lead has diminished markedly and has vanished in some cases. Support for Warren has steadily risen.

But many Democrats, including more moderate voters and party establishment leaders, remain worried that Warren’s agenda, including policies such as the expansion of Medicare to cover all Americans, tilts too far left to win in a general election.