The 1998 midterm election was a debacle for Republicans, particularly then-Speaker of the House Newt Gingrich. Since Reconstruction, no president had seen his party gain seats in the House in a midterm election six years into his presidency. Mr. Gingrich, who made the election a referendum on impeaching President Bill Clinton, resigned after the loss. Clearly, voters had sent the signal, "Don't do it."

The White House thought it had dodged a bullet. But one morning, over Thanksgiving break, then-White House Chief of Staff John Podesta was running in Washington's Rock Creek Park when it hit him: GOP leaders are "not going to let their members off the hook. They're going to beat and beat and beat on them until they vote for impeachment."

It fell to Mr. Podesta to tell the still-celebrating White House staff that the midterms meant nothing, that the push to impeach the president in the House was a runaway train that could not be derailed. "This thing is rigged," Mr. Podesta announced at a Monday-morning staff meeting. "We are going to lose."

President Trump's White House could use a John Podesta about now. Because no one seems to have told Mr. Trump's team that the Democrats are every bit as committed to impeaching Mr. Trump as the GOP was to impeaching Mr. Clinton. The difference, of course, is that the Democrats don't control the House — yet.

If they did, as the Washington Examiner's Byron York rightly noted recently, impeachment proceedings would already be underway. And if the Democrats take back the House in 2018, it won't matter to most members whether the country as a whole supports impeachment, because the voters who elected them — and the donors who supported them — will be in favor of it. (A recent Public Policy Polling survey found that 47 percent of Americans support impeachment while 43 percent oppose it.)

Personally, I think it would be folly to impeach the president given what we know now. But that's meaningless. The phrase "high crimes and misdemeanors" notwithstanding, the criteria for impeachment have little to do with criminal law and everything to do with politics. If 218 members of the House think it is right — or simply in their political interest — to impeach the president, he can be impeached. Whether two-thirds of the Senate decides to remove the president from office is also an entirely political decision. Given the likely composition of the Senate after the next election, however, that remains unlikely.

Then again, who knows? Given how Mr. Trump responds to criticism and political pressure, would you want to bet that the tweeter-in-chief would be a model of statesmanlike restraint during an impeachment ordeal? So many of his current problems are the direct result of letting his ego or frustration get the better of him. What fresh troubles would he mint when faced with removal from office? What might he say under oath to the special counsel? Mr. Clinton, recall, was impeached and disbarred because he perjured himself in a deposition.

House Minority Leader Nancy Pelosi has cautioned against making the midterms a referendum on impeachment. But that is an electoral strategy, not a plan for when she gets the speaker's gavel. And even if she declines to go straight to impeachment hearings on Day 1, a Democratic-controlled House would still be a nightmare for the White House. Any hope of passing a conservative agenda would die instantaneously. Worse, once Democrats gained the power to subpoena documents and compel testimony from members of the administration, the Hobbesian internal politics of today's White House would look like a company picnic by comparison.

In short, the only hope for the Trump presidency is for the GOP to maintain control of the House.

According to various reports, the GOP thinks it can hold on by running "against the media" in 2018. As pathetic as that would be, it might work. Though I doubt it. A better strategy would be to actually get things done.

And the only way for that to happen is for both houses of Congress to get their act together. Voting bills out of the House may be enough to justify a Rose Garden party, but it will do little to sway voters who've been told for years that the GOP needs control of all three branches to do big things. Trump won't be on the ballot in 2018, but his presidency will hang in the balance.

Jonah Goldberg is a fellow at the American Enterprise Institute and a senior editor of National Review. His email is goldbergcolumn@gmail.com. Twitter: @JonahNRO.