Trump's support is cratering — and that leaves him open to a primary challenger in 2020

Associated Press/Pablo Martinez Monsivais

President Donald Trump's terrible, horrible, no good, very bad summer vacation has sent the administration reeling.

With 15 months to go before the mid-terms, the White House still has time to recover, but it is not too soon for Trump's political advisors — if they can pull themselves away from their backstabbing and infighting — to ask a painful question: how vulnerable is Trump to being "primaried"?

No sitting president in the modern era has ever been successfully "primaried" — meaning that he ran for and lost his party's nomination to run for a second term. (Some variant of it happened to several presidents during the 19th century).

That does not mean that incumbents are immune and can ignore the threat. A strong challenge from within his own party helped convince President Lyndon Johnson not to seek reelection in 1968. Strong challenges from within the party contributed to the eventual general election defeats of Presidents Gerald Ford, Jimmy Carter, and George H.W. Bush. Presidents who did win reelection took care to protect their flank and head off any pesky challenges.

(A senior official in the Obama White House told me that the top priority of the administration in the first term was to avoid a challenge from his left flank — a concern that contributed, I believe, to the disastrous decision to hobble the Afghan surge with the arbitrary withdrawal timeline pegged to the presidential electoral calendar.)

Even before the political crisis sparked by his response to the violence in Charlottesville,  Trump was already dealing with rumors of primary threats (see here, here, here, and here). His team responded with the expected bluster about how solid his support is among the base. But as the president's approval among core Republican constituencies craters, such bombast increasingly may sound like whistling past the graveyard.

Trump's polling numbers suggest that his base support is still strong enough to deter challenges, but it's slipping (and maybe worse than that). Even before the president's disastrous post-Charlottesville damage control, there were signs that some prominent supporters were having second thoughts. Since then, the signs have been impossible to ignore.

So how vulnerable is President Trump? My bet is that it's greater than his tweets have thus far acknowledged, and ironically it's precisely because of his tweets — or rather because of the indiscipline for which the tweets are Exhibit A.

Surely someone from the #NeverTrump wing will challenge the president, perhaps Sen. Ben Sasse. I think Sasse is presidential timber, and he may well run in 2020. However, I think the greater threat to Trump would come from outside of the ranks of #NeverTrumpers.

Associated Press/Alex Brandon

The most formidable primary threat would be someone who could plausibly make a claim on a non-trivial segment of Trump voters — i.e. not someone who has opposed him from the beginning and throughout. But that person then has to make the case that Trump has shot himself in the foot with all the tweeting and the scandals.

The strongest primary challenger to Trump is someone who can say, I will give you the Trump agenda without Trump indiscipline. Someone who has been with the president at least since the general election, and so cannot be accused of trying to undermine him, can make a credible case that the president has undermined himself. Someone like that would have a shot at peeling away Trump's core support.

If you want to know what someone like that sounds like, read this remarkable op-ed by one of Trump's most prominent intellectual supporters.  A politician who could translate that angst into campaign soundbites would have a shot at peeling away Trump's core support.

But to be successful the primary challenger would also have to be someone with the competence, record, and policy stances that would appeal to the rest of the party — especially to the deep pockets that could raise enough money fast enough to withstand the inevitable Trump counterattack.

President Trump has alienated most of the Republican mainstream, including the powerful GOP leaders on the Hill who collectively have a lot of experience with campaigns and elections and, in most cases, are more popular in their districts than is Trump himself. While no party in the modern era has officially turned against their incumbent, it does not take a wild leap of the imagination to believe that President Trump could break with precedent.

The successful challenger could build a coalition around a platform consisting of what used to be Trump themes — "they are laughing at us," "we don't win anymore," "we are weak and indecisive," "they attack us with impunity" — but this time claiming that it is Trump himself who has made that problem worse.

The challenger would have to argue that Trump has made the country a laughingstock that doesn't get respect anymore, Trump does not seem to win, Trump seems to dither with indecision when faced with difficult national security choices, Trump lets other countries attack America without responding, and Trump ties himself in rhetorical knots to avoid naming obvious enemies.

Associated Press/Susan Walsh

Those charges will resonate with Trump's base because they were precisely the list he persuasively leveled at Obama and Clinton. Now he is in danger of being hoisted on his own petard. The challenger would argue that Trump was right to want to Make America Great Again, but he just did not have the discipline to see it through.

Of course, President Trump has accomplished some significant campaign promises, including appointing a Supreme Court justice who is well-regarded by Republicans and rolling back some of the onerous regulations of the Obama era. But the president has not yet accumulated the kind of policy record that would make him impregnable.

Crucially, Trump seems to keep putting himself at risk through his own actions. The key bit, I think, is the tweeting and off-the-cuff but on-the-record musings, which symbolizes a president who cannot stop himself from thwarting his own policy agenda.

Of course, the tweets and musings by themselves are not the entirety of Trump's problem, but they are a vivid and easily understood manifestation of it. And they are remarkably unpopular with virtually every sub-demographic in the Republican Party (and beyond).

By focusing on the tweets and the way that Trump has undermined his own policy efforts, a primary challenger might just be able to drive a wedge between the president and his base. It is a more-in-sorrow-than-in-anger posture: "I supported the president's agenda and worked hard to advance it, but every time we started to get traction, the president got distracted and made some glaring and needless error."

I think there are political figures within the Trump Team, broadly defined, that might fit the "reluctant challenger" profile described here. If Trump does not regain momentum, they may be tempted to try their luck in the primaries.

It is far too soon for them to show their hand, but it is not too soon for President Trump's political team to warn the president about what he is doing that contributes to this danger.

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