Dan Pfeiffer, a former top aide to President Barack Obama, told The Daily Beast in an interview released Thursday that he doesn’t believe Congress will impeach President Donald Trump.

Reminiscing on the impeachment proceedings of President Richard Nixon, Pfeiffer said contemporary Congressional Republicans are too loyal to support removing President Trump. “Nixon went down because a number of Republican senators told him that they were going to convict him on the impeachment,” the Obama White House aide told the Daily Beast. “There is no world in which that happens with today’s Republican party. They will not do that. The only way Trump will leave office is voters sending him home.”

Pfeiffer’s comments come after Senator Jon Tester (D-MT) dismissed calls from within the Democratic Party to impeach Trump, describing the idea as both “silly,” and “not appropriate,” in a recent interview with HBO’s Vice News Tonight. “I just think it’s silly talk. I mean, I think it’s not appropriate, at all. I don’t think the investigation that’s been done on Russia—the information isn’t back yet. And, it’s way, way, way, way, way premature,” Tester said when asked for his thoughts on his congressional colleagues plotting to remove President Trump.

In a rare move, the Montana lawmaker later urged fellow Democrats to delay impeachment talk until after special counsel Robert Mueller’s Russia probe is complete. “Once you get the facts, then understand what those facts are really saying, and then hold people accountable. And I don’t think … what he did is going to be an impeachable offense, if he did anything,” he conceded.

The issue of impeachment has divided Democrats since President Trump fired FBI Director James Comey in May 2017, pitting the progressive wing of the party establishment lawmakers who want to avoid the subject. Rep. Al Green (D-TX) offered articles of impeachment in January After President Trump purportedly referred to African countries as “s—tholes,” accusing him of inciting “hate and hostility.” The House voted to table the impeachment resolution on a vote of 355-66. The House blocked Green’s first impeachment effort the month prior. In April, House Minority Leader Nancy Pelosi dismissed efforts by far-left billionaire Tom Steyer to impeach President Trump, calling it a “gift,” to Republicans.

“I don’t think we should be talking about impeachment. I’ve been very clear right from the start,” the 78-year-old lawmaker told reporters on Capitol Hill. “On the political side I think it’s a gift to the Republicans,” she added. “We want to talk about what they’re doing to undermine working families in our country and what we are doing to increase their payrolls and lower their costs.”