Unless they are auditioning for the thankless job as Donald Trump’s vice president, most congressional Republicans probably prefer dental surgery to commenting on Stormy Daniels’ testimony about her alleged affair with the former president. 

Unless they see themselves as foreign policy experts, most congressional Democrats prefer not to reflect on Joe Biden’s sputtering efforts to limit the civilian carnage from Israel’s attack on Rafah. 

In prior decades, congressional incumbents could march to their own drummer without worrying unduly about the top of the presidential ticket. But this year Republicans are inextricably wedded to Trump, and Democrats are stoutly tied to Biden, because the era of split-ticket voting is virtually over. 

In 2020, according to the respected academic pollsters at American National Election Studies, or ANES, 90 percent of Biden and Trump voters also opted for a congressional candidate of the same party.

The Pew Research Center found in the off-year 2022 elections that only 6 percent of voters switched their party allegiance and opted for a congressional candidate from a different party than they backed for president in 2020. 

The New York Times, which loves ballyhooing horse race polls nearly six months before the election, released a new set of surveys Monday with dire news for Biden in swing states. But an accompanying article showed Democratic Senate incumbents in four battleground states (Arizona, Nevada, Pennsylvania and Wisconsin) with comfortable polling leads over their GOP challengers.

But even these premature Times polls do not herald the return to an era when many Americans boasted about voting for the candidate rather than the party.   

As the Times reports, “Ticket-splitters are not abundant — about 10 percent of Trump voters back the Democratic candidate for Senate in the four states, while about 5 percent of Biden supporters back the Republican.”

This level of partisan rigidity is relatively new. 

In 1976, according to ANES, more than one-quarter of voters split their ticket between president and Congress. The numbers were similar in 1988, another year without a significant third-party candidate confusing voting statistics. 

In 1988, because of a quirk in Texas election laws originally crafted for Lyndon Johnson, Democratic Sen. Lloyd Bentsen simultaneously ran for reelection and vice president on a doomed ticket with Michael Dukakis. The power of ticket-splitting was demonstrated when Sen. Bentsen ran nearly 800,000 votes ahead of Vice President Bentsen.

The difference between presidential and congressional voting patterns in those days can be partially explained by how slowly Southern states made the transition to the Republican Party. As a result, moderate House Democrats like John Spratt in South Carolina held on to their seats until the 2010s.

By 2012, the last normal presidential election without Trump on the ballot, 89 percent of the electorate voted a straight ticket for president and Congress. As both parties became more ideologically uniform, there was less temptation for voters to pick one candidate from Column A and another from Column B. 

There are, of course, congressional incumbents in both parties who have convinced themselves that they can prevail regardless of the outcome of the presidential race. 

And they may be right. Sens. Jon Tester in Montana and Sherrod Brown in Ohio are the two great Democratic survivors in red states. Moderate Republican Larry Hogan is trying to pull off a similar trick in the Maryland Senate race. 

But every four years it gets harder to defy gravity.

Part of it is the dramatic decline in the power of TV advertising. If television spots don’t persuade, it is much harder for a candidate to send the message to the electorate “I’m really independent and my voting record is different from my party’s.”

A recent article in The Wall Street Journal detailed how commercial brands are abandoning network television as virtually all shows (except live sports) fail to deliver the expected audiences of yesteryear. 

As the Journal reported, “Brands have been preparing for the inevitable decline of television for years, but many had held out hope that the rise of ad-supported streaming TV would plug the gap. So far, that isn’t happening.” For one thing, advertising-supported streaming services show far fewer commercials per hour than old-fashioned television.

Political campaigns in both parties are almost always lagging behind major commercial advertisers. But this could be the election when voters never hear most political messages. Part of it is that the presidential race will drown out everything else. 

Even compared with the two previous Trump campaigns, 2024 seems likely to offer little more than scorched-earth politics. Trump’s totally invented claims of a stolen 2020 election, his never-ending legal problems and his increasingly scabrous attacks on his rivals mean his antics will dominate the campaign dialogue in the summer and fall. 

Do Republican House incumbents in Biden districts really believe that they can break through the cacophony with their pet issues? And, by the way, what is the GOP’s favorite argument? “Give us the majority again because we were so responsible — we only had two speakers.”

Similarly, if Biden massively underperforms, do endangered Democrats actually nurture the fantasy that they can escape on their own private lifeboats? This is not a year when any rational voter should believe in ticket-splitting — and that a Democratic Congress could contain a President Trump bent on vengeance.

The message for congressional incumbents in both parties: No matter how you feel about the candidate at the top of ticket, whether it is Trump or Biden, realize that you’re stuck with him come November. That’s what happens when almost no one splits their tickets.

Walter Shapiro is a staff writer for The New Republic and a lecturer in political science at Yale. He is a veteran of USA Today, Time, Newsweek and The Washington Post.