Would a Trump Impeachment Help Democrats in 2018?

President Donald Trump smiles during the Infrastructure Summit with Governors and Mayors at the White House in Washington, June 8, 2017. REUTERS/Yuri Gripas

Following the resignation of Republican President Richard Nixon in 1974, a Democratic wave helped the party retain control of the House for two decades. With President Donald Trump's administration facing an ever-growing Russia scandal, Democrats are hoping the 2018 midterms could create a similar wave.

History suggests a president's popularity may be an indicator of electoral success following impeachment or resignation and Trump's approval currently sits at a miniscule 36 percent, according to Gallup. At the time of Nixon's resignation, only 24 percent of Americans approved of him. President Bill Clinton, the only popular president to be impeached, did not see electoral loses amid impeachment discussion, but Clinton was very popular, with a 73 percent approval rating shortly after he was impeached.

Some Democrats, most notably U.S. Representatives Al Green of Texas, Brad Sherman of California and Maxine Waters of California, have publicly called for Trump's impeachment in recent weeks, but Democratic leadership has largely steered clear of the "I-word," with Senate Majority Leader Chuck Schumer and House Minority Leader Nancy Pelosi encouraging members to avoid impeachment talk without clear proof the president broke the law.

Regardless of their stance, Trump's embattled presidency has many Democrats increasingly confident they can hold their position in the Senate and make up ground in the House-or even flip it. Despite what many predicted would be a difficult Senate map for Democrats in 2018, a CNN poll in April found 50 percent of voters would support a generic Democratic candidate in 2018, compared to 41 percent who favored a generic Republican candidate.

There isn't much precedent for what would happen if Trump left office in disgrace. The two impeachments in U.S. history-Andrew Johnson's in 1868 and Clinton's in 1998 - were both followed by acquittal in the Senate and did not seem to play a major role in future elections. Nixon resigned before getting impeached.

Following Nixon's August resignation and Republican President Gerald Ford's decision to pardon him in September, Republicans lost 48 seats in the House and five in the Senate. The "Watergate Babies" elected in 1974 helped Democrats retain control of the House until 1994.

"You had the double hit of one president resigning and the other president pardoning the former president," said Tim Naftali, a presidential historian at New York University.

Many believe the lingering effects of the Watergate scandal also contributed greatly to the election of Democrat Jimmy Carter in 1976. Carter was seen as an outsider and campaigned on his integrity, famously saying, "I will never lie to you." American voters narrowly elected the little-known Georgia governor.

But impeachment hasn't always lead to electoral success for the opposing party.

The Monica Lewinsky scandal plagued Clinton in the lead-up to the 1998 midterms, but did not seem to have a major effect on the election, disappointing GOP leaders. Then-Speaker of the House Newt Gingrich had expected Republicans to increase their majority in the House, but the election saw Democrats pick up five seats.

A few years later, following Clinton's acquittal on charges of obstruction of justice and perjury in the Senate, Democrats gained further seats in the Senate and House in the 2000 election. And Democrat Al Gore won the popular vote for the White House, though Republican George W. Bush went on to win the Electoral College and thus, the presidency.

"I think it's fair to say Clinton's impeachment did not have the political effect on Democrats that Nixon's had on Republicans," Naftali said.

The difference could be Clinton's high approval ratings at the time, something Trump does not have. Public opinion polls, along with the election results, hinted that impeachment was not a popular proposition among voters in 1998. According to The New York Times, polls at the time suggested 60 percent of voters opposed the way Congress had been handling impeachment and hoped Congress would move on.

The only other impeachment in U.S. history occurred in a much different political era. In 1868, Johnson was impeached and only escaped removal from office by one vote in the Senate. Johnson, who was widely disliked by the Republican majority in Congress after replacing the assassinated Abraham Lincoln, was impeached for violating a law that intended to restrict him from removing certain office holders without Senate approval.

In the subsequent 1868 election, Johnson was unable to secure the Democratic party's nomination. Republican Ulysses S. Grant won the presidency, but Johnson's Democratic party gained 20 seats in the House as some Southern states were readmitted to the Union. Republicans gained in the Senate, however, and retained control of both houses of Congress.

"It was such a polarized time, and I know that sounds familiar today, but it's hard to say impeachment itself drove the outcome," David O. Stewart, a lawyer and author of Impeached: The Trial of Andrew Johnson, said. "The North was mostly going to go Republican and the South mostly was going to go to Democrats."

Stewart said that some Republicans were worried that impeaching Johnson would make him a political martyr, and it would be easier for the party to win the 1868 election if they were running against him. He said while the talk about impeaching Trump and replacing him with Vice President Mike Pence is "very premature," he sees a parallel between the Republicans of 1868 and the Democrats today in that some seem to believe leaving the controversial president in office could lead to increased electoral success.

"I've seen lots of talk about how it's better to have Trump tweeting and saying things that puzzle people than to have the outwardly more serene Pence, that it would be easier to run against Trump," he said.

The key to 2018 may come down to the voters who elected Trump, Naftali, the presidential historian at New York University, said. Naftali said it's impossible to tell if the "angry voters" who elected Trump will stick with the president if he disappoints them.

"We have this very strong contingent of voters and we don't know what their loyalty threshold is and what might happen to them if they get disappointed," he said.