Washington (CNN) President Donald Trump's campaign held a background call with reporters Sunday evening where officials laid out their view of the Democratic race and argued that former Vice President Joe Biden and Vermont Sen. Bernie Sanders are interchangeable.

As the Democratic race has become a two-man contest between Biden and Sanders, multiple sources say. Trump has been frustrated by the former vice president's comeback. That was evident in the call the campaign held Sunday night — something they now say they will do so periodically until November — as officials contended that electing Biden is the same as electing Sanders.

While the Trump campaign insisted it doesn't matter which candidate they face, the campaign's communications director attacked Biden's views on health care, immigration, the Green New Deal and gun control.

"They are two sides of the same coin," Tim Murtaugh said. "There's no thought about it."

Democrats would argue otherwise.

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