In California’s on-going resistance to President Donald Trump, a constant theme is to get Trump out of office either through impeachment, an effort led by San Francisco’s Tom Steyer, or via the 2020 election. A number of Californians are potential challengers to Trump from Steyer, to Sen. Kamala Harris, LA Mayor Eric Garcetti and a number of congress members. But observing this political power game, it is clear there could also be a threat to the president out of California from the Republican side.

If not for a constitutional prohibition, it would be a solid bet that former California governor Arnold Schwarzenegger would strongly be considering a run for the presidency. He is at odds with Trump on many issues, highlighted by their back and forth jibes on Twitter over the years.

While Schwarzenegger can’t run for president because he was not born in the United States, he is encouraging others to take up the challenge. It is an approach to promote his New Way movement to remake the Republican Party. Supporters of the New Way effort largely blame Trump for the shellacking California Republicans took in the recent election. In particular, Schwarzenegger has talked to out-going Ohio governor John Kasich, a 2016 GOP presidential candidate, about giving the race another go in 2020.

So far, Kasich has shied away from presidential talk. However, like Schwarzenegger, he too has been very critical of Trump.

The odds are stacked high against a challenger to a sitting president wresting the party nomination away. However, you have to ask what is the goal of a presidential challenger? The first goal would be to win, of course. But there could be a second goal depending on the animus toward the president from the challenger: Removing the incumbent from office.

On that second point, the record is much better for challengers. Look at the history of the 20th century.

In 1992, former Richard Nixon aide Pat Buchanan went after President George H. W. Bush making a strong showing in the opening New Hampshire primary. Bush eventually lost to Democrat Bill Clinton.

In 1980, Massachusetts Senator Ted Kennedy challenged incumbent Jimmy Carter who fell to Republican Ronald Reagan in the General Election. Reagan, himself took on incumbent Gerald Ford in 1976 after Ford took office when Nixon left during the Watergate scandal. Ford then lost to Carter.

Both Robert Kennedy and Eugene McCarthy ran against their party’s president, Lyndon Johnson, to protest the United States position in the Vietnam War. LBJ decided to call it quits. The same was true for President Harry Truman after he lost the 1952 New Hampshire primary to Tennessee Senator Estes Kefauver.

Early in the century, former president Teddy Roosevelt tried to take the Republican nomination from his successor, William Howard Taft, only to be rebuffed by the GOP delegates. Roosevelt mounted an independent campaign with California governor Hiram Johnson as his running mate and both Roosevelt and Taft finished behind Democrat Woodrow Wilson in the election.

The history lessons are there. If the goal is to challenge an incumbent of your party the road is rocky. If the goal is to see the president doesn’t serve a second term the road is smoother.

For Schwarzenegger and his Never Trump allies, efforts to change the direction of the Republican Party to a New Way would be a motivator to keep the pressure on Kasich to make a run.