In 1994, at a time I was covering the White House for the Baltimore Sun, early November seemed like a good time to play in an adult baseball league tournament in Arizona. I mean, what could go wrong?

Sure, President Clinton would take a few lumps. The new president’s party always loses some seats in the midterm elections, but that’s no big deal. As for the Republicans’ “Contract With America,” that sounded to me like boilerplate conservatism. So I was celebrating a double-header sweep in the hotel hot tub with some teammates when I learned otherwise. Summoned to the house phone by my unhappy bureau chief, I was taught a valuable lesson: Never assume you know how elections will turn out.

Newt Gingrich’s “Contract With America” helped the GOP gain 54 House seats – and turned its author into Speaker of the House Gingrich. For good measure, the Republicans picked up eight Senate seats – few observers figured the Senate was even in play – putting Republicans in control of the upper chamber, too, and leaving Bill Clinton sounding like a teenager who’d been suddenly ostracized in high school.

“I am relevant,” Clinton insisted. “The Constitution gives me relevance.”

Democrats are hoping President Trump will feel Clinton’s pain seven weeks from now. But can control of the U.S. House of Representatives realistically go to the Democrats? How about the Senate -- will it change hands? Hundreds of public opinion polls, thousands of newscasts, and millions of words will be expended on this topic between now and Nov. 6 as party professionals and election gurus pore over the 35 Senate races state-by-state while scrutinizing each competitive congressional district.

Like big-wave surfers waiting anxiously on their longboards, these political junkies are scanning the horizon to see if they detect the looming arrival of a monster swell.

“Wave” elections can be difficult to discern, but for those of you not obsessed with national politics, here is the terrain: The House currently has 236 Republicans, 193 Democrats, and six vacancies. All of them are up in 2018, and the upshot is that Democrats need to flip 23 GOP seats to gain control. How hard is that to do? The short answer is: harder than it used to be, thanks to gerrymandering. But possible.

In the Senate, the task should be easier for Democrats because they hold 49 of the chamber’s 100 seats, meaning that they only need only a net gain of two. Their problem is that of the 35 Senate seats up for election in 2018, 26 are held by Democrats – 10 of them in states Donald Trump carried two years ago.

So what’s the evidence of a big, blue, Democratic wave? At least three signs point in that direction; let’s examine them one at a time.

All Politics Are National

Iconic 20th century House Speaker Thomas “Tip” O’Neill famously proclaimed that all politics is local. Strictly speaking, this was never true: O’Neill was reminding his troops to remain visible in their home districts. But politics has been so thoroughly polarized today that – even more than was historically true -- the 2018 midterms are a referendum on the policies and personality of Donald John Trump.

A rule of thumb is that when the president’s job approval rating is in the high 40s or 50s, his party tends to weather the storm. Trump is in the low range – 42.2 percent in the RealClearPolitics poll average – with a particularly high disapproval rating: 53.7 percent. In the last “wave” election, President Obama was at 44 percent, and Democrats lost 63 House seats, and the Senate. That was 2010. But as Doug Usher, a political consultant for Purple Strategies, points out, Jimmy Carter’s number four decades ago was identical to Trump’s – and Democrats only lost 15 seats. That wasn’t enough to cost Tip O’Neill the speaker’s chair and it wouldn’t be enough to put Nancy Pelosi back into it in 2019.

GOP loyalists insist there’s little precedent for a sea-change election when the economy is this strong, but the economy is already baked into the cake; i.e. it informs the president’s job approval rating. What worries Republicans is that the robust economy hasn’t boosted Trump’s popularity higher. One silver lining for Team Trump? He does significantly better in polls of “likely” voters. Trump himself grasps the implication of this distinction – and what’s at stake if his party loses the levers of power on Capitol Hill.

At a recent Montana rally, Trump castigated the special counsel’s investigation and suggested that if Democrats come to power, they would use it to pursue impeachment. “It’s so ridiculous,” he said as the audience laughed along with him, “but if it does happen it’s your fault…because you didn’t go out to vote!”

My Party’s Bigger Than Your Party

The other number causing heartburn inside the White House and among Republican congressional candidates is what pollsters call the “generic ballot.” Basically, this asks Americans whether they intend to vote Republican or Democrat.

Right now, Democrats lead Republicans, 48.8 percent to 40.8 percent, in this category. In the past, Republicans have outperformed this number, but eight points is a big gap and the Democrats’ lead is holding steady. There isn’t any real way to spin this, as David Wasserman of the Cook Political Report explained in August:

“If the generic ballot gap between the parties stays as it is or grows larger, while the president’s approval rating remains much the same (as it has for most of 2018), the odds of a GOP House are going to be pretty limited, unless the president’s party wins a remarkable number of close races.”

The Candidates

Wasserman is one of several election analysts who keep track of individual House races. University of Virginia professor Larry Sabato is another, along with Nate Silver of 538, Nathan L. Gonzales of Inside Elections, and RealClearPolitics’ Sean Trende. In various examinations of individual House districts these analysts have highlighted races in which Democrats did well in special elections in places where they shouldn’t be competitive. This phenomenon, says Trende, “is indicative of greater energy on the Democratic side.”

Another factor is the strong Democratic recruitment efforts. This is unglamorous work, and it takes place a year or two before the campaigns begin, but Democrats have fielded a class of candidates that includes numerous military veterans, accomplished women, and minority candidates that fit their districts and states.

At Democratic National Committee headquarters, the poster child for this effort is Beto O’Rourke, a charismatic young congressman running only four or five points behind Texas Sen. Ted Cruz. In a true wave election, these are the kind of races the party in power loses. Those 25 tossup House races? In an electoral tsunami of the type that last happened in 2010, those seats are all lost by the party in power, along with another two or three dozen. That’s what a wave looks like.

Could Beto O’Rourke and a cohort of millennial generation House candidates usher in just such tidal wave? It’s beginning to feel that way. If so, however, what the heck happened on Tuesday in a state Senate race on the Texas-Mexico border? Well, what happened is that an affable Republican named Peter Flores prevailed in a district that Democrats had held for 139 years.

At least one Republican said he wasn’t surprised. Newt Gingrich weighed in afterward, saying a wave election was coming, all right – a red one. And that, as they say at the track, is why they run the races.