In the middle of the first presidential impeachment trial, of Andrew Johnson in 1868, Walt Whitman wandered over to Capitol Hill to witness the proceedings. “Our American politics,” the poet told a friend, “are in an unusually effervescent condition.”

A century and a half later – and 127 years after Whitman’s death – our American politics are in an unusually effervescent condition again. In a month that included President Donald J. Trump’s State of the Union address, it became increasingly clear that there were several moving parts to American politics – and that American politics was changing dramatically, and importantly.

Washington Republicans – first resistant to Trump, then the captive of the Manhattan billionaire, more recently resistant again to the president – are in the throes of a profound identity crisis, tethered to a chief executive they revile but cannot repudiate, ardently supporting some of his policies, reluctantly swallowing others. Such conflicting sentiments are exceedingly rare, experienced only by the Whigs who grew impatient with John Tyler in 1841, the Democrats who split under Franklin Pierce in 1856 and James Buchanan in 1858, the Republicans who grew weary of William Howard Taft in 1912, and the Democrats who grew skeptical of Jimmy Carter in 1980.

The two profiles of the president – Prince Charming to some, the Prince of Darkness to others – were apparent during his nationally televised message, especially when he combined an appeal for bipartisanship with his dismissal of the “ridiculous partisan investigations” examining any ties he has to the Russians. The great conflicts of the age were on full display when he issued a generous salute to the women now serving on Capitol Hill, a record 102 female House members, 89 of them Democrats. Many of them were elected to Congress as a rebuke to Trump himself.

But the spectacle on Capitol Hill – the women in suffragist-white, the president alternatively conciliatory and combative, in a speech postponed after the longest government shutdown in history and while the clock was ticking toward another immigration-legislation deadline – was only a part of the rapidly changing scene in American politics.

For years one of the principal struggles in Congress was between Republicans who were troubled about the swiftly mounting costs of Social Security and Medicare entitlement programs and Democrats determined to preserve these benefits. And yet for the last four presidential elections, voters over 65 have sided with the Republican candidate. 

The Democrats now are plotting an offensive to win back those voters, who customarily rewarded Democratic vigilance on Social Security and Medicare with support in presidential elections. Democrats have just introduced legislation in the House, which they now control, to boost benefits by about 2 percent and to adjust payment schedules to the advantage of the very blue-collar voters who migrated into the Trump column two years ago. They would do all this by raising payroll taxes on the wealthy. This is a contrast to the president, who despite his appeal to working-class Americans signed a tax bill that favored wealthy Americans. Under the Democratic plan, Americans with incomes over $400,000 would be subject to a new set of payroll taxes. The change in House control is changing the entire conversation in Washington.

The new capital conversation is apparent in debate over climate change, newly revived by the Democratic capture of the House. This debate was largely dead while the GOP controlled both houses of Congress with a president who believed the concept was a hoax. Last week, there were two House hearings on a so-called “Green New Deal.” This is occurring as (overly optimistic, perhaps unrealistic) House Democrats discuss how to distribute revenues from a carbon tax. Prospects for such legislation are slim, but this is a topic that dared not speak its name only three months ago, when even the consideration of new taxes was inconceivable.

The fresh agenda of Congress also is reflected in new debate over stock buyouts, with three Democratic presidential candidates or potential candidates – Senators Elizabeth Warren, Kirsten Gillibrand and Bernie Sanders – suddenly talking about restrictions on how much stock that companies can buy back from shareholders, an effort to limit the corporate advantages tucked into the 2017 Trump tax bill. 

The biggest new change – the one with the most significant possible consequences – is the emerging Republican view of the president.

Trump, to be sure, won wild applause from the GOP side of the House chamber during his speech Tuesday night when he pushed some of the buttons that reliably set Republican hearts aflutter. Jimmy Carter had the same effect in 1979, when he noted the creation of 7.1 million new jobs and the reduction of unemployment by a quarter and then, in an attempt to rob Sen. Edward M. Kennedy of his signature issue as he contemplated an audacious primary challenge to the president, spoke boldly of taking “our first steps to develop a national health plan.”

There is no Kennedy-type figure to take on Trump in his re-nomination drive yet, but Republicans increasingly are resistant to some of the president’s tactics, style and priorities. There was thunderous applause for Trump’s appeals for border security, but the cheers came from Republicans who understand that the House now is a stubborn impediment to the border wall the White House wants far more than congressional Republican leaders do. There was no mention in the president’s remarks about the government shutdown, but it’s clear congressional Republicans will not abide another such spectacle. 

Trump’s relations with Senate Majority Leader Mitch McConnell have changed as swiftly as this winter’s weather in the Northeast – freezes followed by thaws only to be overtaken by new freezes. There is a distinct chill in the congressional air right now, with the Kentucky lawmaker unenthusiastic about the Trump Syria policy and his wall rhetoric and even less eager to support an emergency declaration to begin border construction.

The next few months will be critical for both parties. Somehow the president and Congress will have to find a sliver of common ground to keep the government operating. New Democratic presidential candidates will emerge, and somehow the party is going to have to resolve how it is going to handle a nomination fight with more candidates than a major-league ballclub. 

But all is not lost. Pitchers and catchers start reporting to spring training on Monday. Washington is going to have to start playing ball soon, too. 

David M. Shribman is executive editor emeritus of the Pittsburgh Post-Gazette. He can be reached at dshribman@post-gazette.com.