Democrats didn't know what hit them when they lost control of the House of Representatives in 1994.

That midterm election was historic. Republicans claimed control of the House for the first time in 40 years, capturing a staggering 54 seats. It was the biggest gain of seats for either party since 1948.

And everyone thought the outcome spelled doom for President Bill Clinton.

Four years later, House Republicans went on to impeach the president after his affair with Monica Lewinsky. But Democrats losing the House in the 1994 midterms proved to be one of the best things which ever happened to President Clinton. Then-House Speaker Newt Gingrich, R-Ga., was politically virulent – as were many of the House GOP’s policies.

President Clinton needed a foil. And he earned one in Gingrich and the upstart House Republicans. Gingrich challenged the President over government spending, sparking three government shutdowns. Gingrich and the strident approach taken by House Republicans polluted the 1996 presidential bid of Senate Majority Leader Bob Dole. President Clinton easily vanquished Dole and returned for a second term.

It's possible that losing the House could be the best thing that ever happened to President Trump. His poll numbers are low. He lost badly in the presidential popular vote, failing to hit 50 percent in multiple states. With their new power, Democrats promise exhaustive investigations and inquiries into a host of issues.

"The business of presidential harassment, which we were deeply engaged in in the late '90s, improved the president’s approval rating and tanked ours,” Senate Majority Leader Mitch McConnell, R-Ky., said last week. "My observation is that it might not be a smart strategy. But it's up to them to decide how to handle that."

If anyone ever needed a foil, it's President Trump. No fool he, the president knows how Republicans transfigured prospective House Speaker Nancy Pelosi, D-Calif., into their archenemy more than a decade ago. Democrats must play their cards very carefully, lest they plunge into the historical trap which Mr. Trump could lay for them.

The President has already warned of a "war-like posture" if House Democrats push too far in their inquiries.

"They can play that game. But we can play it better," the president said Wednesday at this post-election press conference Wednesday.

Trump tweeted that his administration would counter Democratic inquests with probes "for all of the leaks of Classified Information and much else, at the Senate level. Two can play that game!"

This is a challenge for Democrats, who partly won control of the House because of what voters interpreted as Republican fealty to the President. Some of the Democrats’ mandate – to say nothing of their Constitutional responsibility – is to conduct appropriate investigations and oversight of the executive branch.

But there is peril in this approach. House Democrats must withstand the urge to make everything about repudiating the administration and the president. This requires balance. And it’s unclear if Democrats can walk that line.

How do they investigate – yet not go too far?

Pelosi held considerable sway when she served as Speaker from 2007 to 2011, but some wonder if she can harness restive Democrats with the same mastery of old. The Democratic caucus is different from the one she presided over in days of yore. Rep.-elect Alexandria Ocasio-Cortez, D-N.Y., surfaced in Pelosi's office Tuesday to take part in a protest about climate change. Never mind that it was Pelosi who muscled the so-called "cap and trade" climate bill through the House when she was Speaker in 2009. Ocasio-Cortez’s maneuver is emblematic of how Pelosi could encounter pressure from some liberals who don’t think she is willing to go to the mat with President Trump – and moderates who think the left is going too far.

This requires finesse.

"I don't think we'll have any scattershot freelancing," said Pelosi last week regarding Democratic inquiries. "When we go down any of these paths, we'll know what we’re doing and we'll do it right."

Naturally, what's too much and what's right falls within the eye of the beholder. Republicans are lying in wait, ready to excoriate Democrats for pushing too far. One can bet that Republicans will portray any Democratic scrutiny of the President as a bridge too far.

"I know what the Democrats want to do. Just investigations and impeachment," House Majority Leader Kevin McCarthy, R-Calif., told Fox Business Network on Sunday. "America is too great to be led by such a small vision."

Pelosi recently sidestepped a question about Democratic endeavors to obtain Trump's tax returns. She's frequently deployed a rhetorical sleight-of-hand, using the word "oversight" rather than "investigations."

President Trump would love to tangle with the Democrats. Aggressive "oversight" by likely House Oversight Committee Chairman Elijah Cummings, D-Md., and probable Judiciary Committee Chairman Jerry Nadler, D-N.Y., complete with exchanges with White House officials from the dais may energize the left-wing base. But this is the type of battle where Trump excels. Brass-knuckle street fights are de rigueur for this president. Pelosi is wise to attempt a measured approach once Democrats formally claim the majority in early January.

But can Democrats keep themselves in check even if they wanted to?

The president will make it hard.

Democrats hit the ceiling when Trump sacked Attorney General Jeff Sessions just hours after they won the House. Democrats fired off letters demanding information on the firing, called for Acting Attorney General Matthew Whitaker to recuse himself on the Russia investigation and demanded action on legislation to inoculate Special Counsel Robert Mueller from interference.

The Democrats' hunger for investigation and revenge may be too much for them to resist the à la carte dishes President Trump serves up on a platter.

Striking the proper balance will likely prove to be Pelosi's biggest challenge if she is to serve as the next Speaker.

Some Democrats say it's time for Pelosi to go and have demanded new leadership at the top of their caucus. Some liberals certainly don't want to hear anything about "measured responses" and "restraint." They would rather rip a page out of the House Freedom Caucus playbook and raise Cain.

That’s why the most compelling case for Pelosi to return as Speaker may be her reputation as someone who has been there before. As Speaker, Pelosi has already tangled with a president of the opposite party. She knows how to take a deliberate approach to investigations and oversight.

President Trump will likely explode at even reasonable efforts by House Democrats to probe his administration. The President understands the value of a foil – in much the same way President Clinton comprehended the significance of Newt Gingrich and GOPers after the 1994 midterms.

Things worked well for Mr. Clinton. If House Democrats aren't careful, they'll stumble into the same trap House Republicans did 24 years ago.