WASHINGTON — When the Republican-led House voted in 1998 to begin an impeachment inquiry into President Bill Clinton, 31 Democrats sided with Republicans, and the White House breathed a sigh of relief that the number was not significantly larger. In today’s hyper-polarized Washington, defections of that magnitude on the question of impeachment would be considered a tsunami.
Not a single House Republican on Thursday joined Democrats in supporting a resolution outlining the parameters for the next stage of impeachment proceedings, despite having demanded such a vote for weeks. Just two Democrats broke from their party to oppose the investigation.
The stark division in the 232-to-196 vote made clear that the accelerating impeachment inquiry will continue to be highly partisan as it moves into its more public phase, with the two parties pulling ever further apart as they dig in deeper on the righteousness of their respective causes.
Democrats say it is their constitutional duty to hold a lawless President Trump to account even if he is unlikely to be removed from office. Republicans are determined to defend a president they say is being persecuted for political gain. Little evidence has emerged that either side is willing to give an inch, and the certainty of facing a major political backlash for doing so would seem to decrease chances of that prospect even further.
“It shows the bases are controlling both parties,” said Representative Peter T. King, Republican of New York, who ended up voting against Mr. Clinton’s impeachment in 1998, about the sharp lines being drawn.
More than a few Republicans have privately expressed qualms in general about Mr. Trump’s actions, and in particular about his attempts to persuade the Ukrainian government to investigate former Vice President Joseph R. Biden Jr., a potential 2020 presidential rival, and his son Hunter. Yet none risked stepping forward during the first significant impeachment floor vote to suggest that the president’s conduct merited at least a review. Some of those who had been seen as potential Republican backers of the inquiry attributed their opposition to the way House Democrats have handled it so far.
“I have been absolutely clear that from the beginning I wanted to see an open, transparent and fact-based process because I have been troubled by what has come out,” said Representative Fred Upton, Republican of Michigan, who dined with Mr. Trump days before the vote. “Legitimate questions remain to be answered. But I have been frustrated by how closed off the process has been so far.”
Polarization has consequences, and Democrats have been concerned from the start about running what Speaker Nancy Pelosi repeatedly called an inherently divisive process. The mostly party-line vote threatened to undermine public confidence in the proceedings, making it easier for voters to dismiss it as yet another skirmish in an endless partisan war, rather than a weighty constitutional process. Democrats are now faced with the challenge of mounting a compelling case to the public that can cut through the political noise and generate even the barest of bipartisan consensus, knowing that the greater likelihood is that Mr. Trump will be acquitted in the Republican-led Senate.
In President Richard M. Nixon’s case, warnings from members of his own party that he had lost their support forced him from office, and so far, there is no sign of any such movement from today’s Republicans. Although Mr. Clinton’s impeachment began with some bipartisan support, that dissipated and Republicans ultimately paid a steep political price for what was viewed as a partisan effort. In the current toxic atmosphere, there is even less chance that Democrats and Republicans can unite around a common view of what should happen to Mr. Trump.
Democrats had hoped to win support from the likes of Mr. Upton and a handful of other Republicans in swing districts to put a bipartisan veneer on the official call for an inquiry. But with most Republican voters remaining devoted to Mr. Trump, no House Republican saw any advantage in breaking from the president.
Party leaders and the White House also worked feverishly to limit any desertions, with the president wooing possible defectors and top Republicans arguing to colleagues that they needed to present a united front against an unfair Democratic impeachment campaign.
“There were a lot of questions today about whether or not Republicans would stick together on this vote and do the right thing for the country,” said Representative Steve Scalise of Louisiana, the No. 2 House Republican. “I can tell you that our conference stood strong.”
Republicans also say nothing has emerged to justify impeaching the president and removing him from office, instead accusing Ms. Pelosi and her chief lieutenant in the inquiry, Representative Adam B. Schiff of California, the chairman of the Intelligence Committee, of pursuing the president to appease Democratic voters. Republicans derided the Democratic push for impeachment as a sham, a disgrace, a charade, a Soviet-style mock trial and an effort to overturn the 2016 election and impede the 2020 campaign.
Democrats say they essentially called the bluff of Republicans by holding a vote to officially endorse an impeachment inquiry. Republicans had hammered them for weeks for not voting to open an inquiry even though the House had held such votes in the cases of Mr. Clinton and Mr. Nixon.
Democrats believe that they have taken a step toward neutralizing Republican complaints about how the inquiry is being conducted — though Republicans kept up that drumbeat Thursday — and that Mr. Trump’s allies will now have to focus more on the substance of the inquiry. Democrats believe they have an advantage on that front, with multiple witnesses appearing before a combined three committees to corroborate a whistle-blower complaint that the president was using the power of his office to pressure a foreign ally to help him with domestic politics. To Democrats, that is inarguably grounds for impeachment.
“We are not here in some partisan exercise,” Representative Jim McGovern, the Massachusetts Democrat who leads the House Rules Committee, said Thursday. “There is serious evidence that President Trump may have violated the Constitution.”
Despite the unanimous Republican resistance, Democrats also believe that continuing disclosures, coupled with wall-to-wall television coverage of public hearings, could pressure some Republicans to be more receptive to the idea of supporting articles of impeachment as the inquiry proceeds.
The strong Democratic vote behind the inquiry represents a significant shift from where the party was just a few months ago, when many moderate Democrats — the key to the party’s majority in the House — expressed strong reservations about moving to impeach Mr. Trump with an election set for next year. But the revelations about Ukraine eased the concerns of all but two Democrats, Representatives Collin C. Peterson of Minnesota and Jeff Van Drew of New Jersey, who sided with the Republicans. That led Republican leaders to declare that the only bipartisan vote Thursday was against the inquiry.
Should the intense House partisanship over impeachment remain, it is very likely to influence events in the Senate. Republican senators have said repeatedly that a highly partisan process in the House will result in a highly partisan outcome in the Senate, where Republicans are in the majority and have so far shown no inclination to entertain the Democratic call to oust the president. The near-blanket Republican refusal to challenge the president troubles one of their former colleagues.
“You just want to tell these Republicans that at some point you are going to have to face the facts,” said Jeff Flake, a frequent critic of Mr. Trump and a former Republican senator from Arizona. “You can decide that it is not impeachable behavior, or it will draw the country through a process we shouldn’t go through. But to defend the president and to support him for re-election when you know what you know is just beyond the pale.”
For the moment, what House Republicans and Democrats know is that they remain bitterly divided over a quickening inquiry likely to end in a House vote to impeach the president.