President Trump's best strategy for attacking Sen. Elizabeth Warren (D-Mass.)? Racism, apparently.

Trump made an early enemy out of the now-2020 candidate, labeling her "Pocahontas" in an offensive attempt to attack her Native American heritage. Warren's attempt to counter Trump backfired, but she still managed to outride his racist taunts, and now Republican strategists fear Trump wasted his best insults long before Warren was at her peak, The Daily Beast reports.

Republicans have scattered attacks on Democratic candidates throughout the 2020 race, but have had little success going after Warren, The Daily Beast's interviews with 10 Republicans, including Trump campaign and White House officials, reveal. "We all push out the bad Warren stories but they don't go very far," one GOP strategist said. And some of those that do take hold, such as reporting on Warren's Republican past, have even been spun to benefit Warren.

Warren worries have reportedly even reached the Oval Office. Trump, aides, and allies all privately spent the past year taunting Warren and suggesting she'd be the easiest 2020 contender to take down, The Daily Beast reports. But now Trump has suggested Warren will be "tougher" to beat than he expected, and even asked a room of advisers if they "thought Warren was a 'fighter,'" three people who recently talked to Trump about Warren tell The Daily Beast. To counter all that uncertainty, the Republicans interviewed said they expect Trump and GOP attacks on Warren to escalate in the next few weeks.

Read more at The Daily Beast. Kathryn Krawczyk