Jonathan Tobin explains at National Review Online how U.S. Sen. Elizabeth Warren’s potential presidential bid already faces a formidable challenge.

Senator Elizabeth Warren thought she was solving a problem that presented a clear obstacle to her presidential ambitions. But it turns out that taking a DNA test to disprove President Donald Trump’s taunts disputing her claims of Native American heritage didn’t just fail to shut him or other conservative critics up: It also exposed her to the sort of criticisms from the left that may turn out to be fatal to her hopes of winning the Democratic presidential nomination in 2020.

That was the upshot of a Thursday New York Times feature that made it clear Warren’s nascient 2020 campaign is already in deep trouble. With Native American groups and others on the left claiming that her actions betrayed insensitivity to the issues of tribal identity and racial oppression, some in Warren’s camp are speculating that her only way out of the mess is to apologize for taking the test. Other advisers, speaking off the record, assert that whether or not she apologizes, there’s no way for the senator to avoid confronting the issue before she formally announces her intent to run.

This is not exactly the position the Massachusetts senator thought she’d be in a couple of months ago. Most Democrats rated Warren a top-tier candidate in an overcrowded field of veteran politicians and newcomers.