Conservative commentator Johnny Burtka argued Tuesday that Sen. Bernie Sanders Bernie SandersTrump, Biden will not shake hands at first debate due to COVID-19 Sanders tells Maher 'there will be a number of plans' to remove Trump if he loses Sirota reacts to report of harassment, doxing by Harris supporters MORE (I-Vt.) is best equipped to take on President Trump Donald John TrumpBiden says voters should choose who nominates Supreme Court justice Trump, Biden will not shake hands at first debate due to COVID-19 Pelosi: Trump Supreme Court pick 'threatens' Affordable Care Act MORE on the debate stage.

“Bernie clearly has the pugnacity,” Burtka, executive director for The American Conservative magazine, told Hill.TV. “He’s the only one that I think could ultimately take on Donald Trump on the debate stage.”

Burtka said that Sanders and fellow 2020 contender Sen. Elizabeth Warren Elizabeth WarrenOvernight Defense: Appeals court revives House lawsuit against military funding for border wall | Dems push for limits on transferring military gear to police | Lawmakers ask for IG probe into Pentagon's use of COVID-19 funds On The Money: Half of states deplete funds for Trump's 0 unemployment expansion | EU appealing ruling in Apple tax case | House Democrats include more aid for airlines in coronavirus package Warren, Khanna request IG investigation into Pentagon's use of coronavirus funds MORE (D-Mass.) have effectively “amplified the progressive voice” in the Democratic race by largely avoiding direct attacks on each other.

“It seems like there’s been a multiplier effect in terms of the progressive energy that’s coming from Bernie and Warren,” he said.

“They’ve done a great job on the debate stage playing off each other, eventually they’re going to have to decide who's the best candidate.”

Warren and Sanders have been jockeying for second place in polls recently, behind former Vice President Joe Biden Joe BidenBiden says voters should choose who nominates Supreme Court justice Trump, Biden will not shake hands at first debate due to COVID-19 Joe Biden should enact critical government reforms if he wins MORE.

A Quinnipiac University poll released on Monday showed Warren and Sanders in a statistical tie among Democrats and Democratic-leaning independent voters nationwide. Warren had 17 percent support to Sanders's 16 percent, the poll found.

The survey showed Biden still leading the crowded Democratic field with 30 percent support.

All three top-tier candidates are poised to take the stage Thursday night for the sixth Democratic debate. The debate is set to take place at Loyola Marymount University, despite a labor dispute that had threatened its prospects leading up to the event.

—Tess Bonn