In his 2016 campaign and now fourteen months as President, Trump has seemingly redefined the Republican party and despite his relative unpopularity nationwide, has a stronghold on its power. Between Trump’s $1.5 billion infrastructure plan, suspicion of trade agreements, and the general increasing federal budget deficit, he has swayed from traditional American conservatism and isolated members of his own party.

Unsurprisingly, there has been a number of GOP congressmen who have come forward as outspoken critics of the President. Among Trump’s primary dissenters is Jeff Flake, a Republican senator from Arizona who has made a name for himself in attacking Trump.

Most recently, Flake has been leading the charge of those who are calling on the House to impeach Trump if he is to fire special counsel Robert Mueller, who is investigating Trump and campaign for alleged misconduct in connection with Russian interference in the 2016 election. Flake has criticized Trump for negatively changing the face of the GOP away from conservatism, referring to the American conservative as “an endangered species”.

In November, Trump blasted Flake on Twitter for “speaking out against your favorite president”, saying that his “political career is toast” because he wouldn’t vote for the tax cuts and his criticisms against Trump

While Flake actually did end up supporting the tax cuts, his political career is certainly going downhill: he has lost much of his support – especially in Arizona, where Trump is extremely popular amongst Republicans – and has one of the lowest favorability ratings in Congress.

Throughout his brief congressional career, he has flip-flopped on gun policy, which angered many of his constituents as well. Flake, who was elected in 2012, says that he will not run to keep his seat in 2018, likely due to his lack of support.

While Flake’s career in Congress is coming to a close, he is not completely exiting the political scene. He has said on multiple occasions that he hopes that somebody will challenge Trump in 2020 and hasn’t counted himself out as a potential challenger, though he has not definitively said that he would be the one.

There is a likely chance that Trump will face a non-democratic challenger in the 2020 election, either independent or from within the Republican primary.

Stuart Stevens, the chief strategist to Mitt Romney in his 2012 campaign, is one who believes that someone will take the challenge, saying “there’s a certain percentage of Republicans who are unsatisfied with President Trump, and they would need a voice.”

Ohio Governor John Kasich, who ran against Trump in the 2016 Republican Primary, is a name that often comes up in this discussion. Kasich too has been critical of Trump and stated that “all options are on the table” in terms of him challenging Trump in 2020 as a Republican or independent. Kasich has indicated that he will reach across the aisle and compromise in addition to being friendly on immigration.

Historically, incumbent Presidents facing a primary challenger won the primaries with ease but did not fare well in the general election, such as Jimmy Carter in 1980 and George H.W. Bush in 1992, challenged by Ted Kennedy and Pat Buchanan, respectively.

When asked if he would run as a Republican or an Independent, he responded: “I’m a Republican, I’m a conservative, and I just want to add to the public debate and do a good job”. Currently, there are a significant amount of people dissatisfied with Trump, but they aren’t necessarily a unified group. Having a leader like Kasich could give them a figure to rally around. Former actor and California governor Arnold Schwarzenegger indicated that Kasich should run against Trump as well.

There are many who believe that Kasich has a chance to become the first successful independent candidate. In swing states that narrowly voted for Trump in 2016, such as New Hampshire and Michigan, Flake or Kasich could pose a significant threat, albeit not enough to win them the primary altogether.

Trump will be forced to focus on many of these states if he faces a primary opponent in 2020. Kasich could also gain the votes of many moderate Democrats if a radical progressive like Elizabeth Warren runs on the Democratic ticket.

Kasich has a broad appeal and likable personality who can win over many voters who are dissatisfied with Trump but are not seeking a progressive leader, yet he lacks the charisma that is typical of many successful presidential candidates.

There is little chance that any candidate will defeat Trump in the primary for a variety of reasons. Trump likely will have the support of the GOP, and his favorability has increased as a result of the recent passage of the tax reform bill.

Additionally, Trump has remained immensely popular among Republicans in certain regions of the country. But, a competition in the primary may hurt his chances of winning the general election in 2020. He will have to devote resources, money, time, and workers to the primary when he could be focusing on the general election instead.

However, going back into the campaign slog won’t necessarily help him, as he would temporarily go back to being a “normal” politician as opposed to simply being the president and stay above the fray. Historically, incumbent Presidents facing a primary challenger won the primaries with ease but did not fare well in the general election, such as Jimmy Carter in 1980 and George H.W. Bush in 1992, challenged by Ted Kennedy and Pat Buchanan, respectively.

It is nearly certain at this point that barring any major political gaffe or controversy, Trump will indeed run in 2020. While some experts say his ratings may fall low enough where it would not make sense to run, the overwhelming majority say that that will not be the case. Much depends on how Congressional Republicans, specifically those who align directly with Trump, fare during the midterm elections this November.

Trump, who thrives in campaign mode, has already unveiled his slogan for 2020: “Keep America Great”. The midterms will be a good indicator of how Trump Republicanism is being received nationwide and will shed further light on potential challengers in the 2020 election.