Chuck Schumer lost the first impeachment trial battle to Mitch McConnell. But the Democratic leader and his party insist they can still win the war.

While Senate Majority Leader McConnell has locked up enough Republican votes to ignore demands for a bipartisan framework for President Donald Trump’s impeachment trial, his Democratic counterpart is readying a counteroffensive. Schumer will force a series of votes designed to squeeze vulnerable Republicans and harm them on the campaign trail if they side with Trump.

Democrats argue the half-dozen at-risk GOP senators will need some daylight between them and Trump to get reelected. And if they vote against Schumer’s motions to hear new evidence and witness testimony, they’ll be seen as Trump sycophants — undermining their bids and boosting Schumer’s odds of becoming majority leader.

Support for obtaining new documents at the trial is “even stronger than we thought, with large numbers of Republicans supporting it,” Schumer (D-N.Y.) said in an interview. “And when you go against what the American people feel strongly about, on an issue they’re paying attention to, it’s not a good idea.”

Public surveys in key swing states back up Democrats’ claims.

Polling from Hart Research found that 63 percent of voters in Arizona, Colorado, Maine and North Carolina would react unfavorably if their senator voted against calling witnesses or subpoenaing documents during the Senate impeachment trial. Another poll from Morning Consult found 57 percent of voters believe the Senate should call additional witnesses. That includes 71 percent of Democrats, 56 percent of Independents and 40 percent of Republicans.

Given Trump’s fast-paced presidency, there’s no guarantee impeachment is the top issue for voters in November.

But Maine moderate GOP Sen. Susan Collins is already moving to blunt Schumer’s tactics, which she has complained about bitterly. She says she’s working with a handful of Republicans to keep a pathway open for witnesses, flashing some independence from Trump and McConnell.

“I am hopeful that we can reach an agreement on how to proceed with the trial that will allow the opportunity for witnesses for both the House managers and the president’s counsel if they choose,” Collins said in a statement for this story. “It is unfortunate that Chuck Schumer — who voted against witnesses in the Clinton trial and prejudged its outcome — and his allies are seeking to politicize this process.”

Trump national security adviser John Bolton’s offer to testify gives some momentum to Democrats' calls for witnesses and documents about the White House’s decision to withhold aid to Ukraine. Democrats also want to hear from acting White House chief of staff Mick Mulvaney, Office of Management and Budget official Michael Duffey, and Mulvaney adviser Robert Blair.

“If the Republicans ram through process that ultimately leads to no witnesses, I think they do it at their own peril,” said Sen. Robert Menendez (D-N.J.), a former chairman of the party’s campaign arm. “Some of these members: They have an audience of one. But I think they forgot that there’s a broader audience that they’re going to have to face at election time.”

Republicans say that Schumer has the politics all wrong, and that they are merely following the precedent of former President Bill Clinton’s trial. That means starting the trial and deciding on witnesses later. However, Clinton impeachment investigators did not face the same level of stonewalling that the House has faced to date from Trump and Senate Republicans in 1999 eventually sought testimony from key witnesses.

So now that Schumer’s proposal has been rejected, Republicans merely see an effort to save face.

“He can create that narrative, I’m not the least bit worried about it,” said endangered Sen. Thom Tillis (R-N.C.). “Sounds like he’s trying to make lemonade out of lemons.”

“Everybody believes Sen. Schumer’s going to play a game with impeachment to try and get back the Senate,” said Sen. Lindsey Graham (R-S.C.), also up for re-election. “He wakes up every day trying to be the majority leader.”

Yet concentrating on process may also be good politics for Democrats.

“It’s a popular issue across America. I’ve not heard any blowback from it. Why wouldn’t someone want to hear from witnesses with firsthand information?” asked Doug Jones of Alabama, the most vulnerable Democratic senator facing reelection. He said not a single constituent “has said that’s an unreasonable position.”

Crossing Trump and being seen as following Schumer’s marching orders would court disaster for most GOP senators, who can’t afford to alienate their party’s conservative base. And Democrats are eager try to capitalize on Republican votes against new evidence in the impeachment trial.

And given slim hopes of most major legislation getting passed in the Senate this year, the impeachment votes may be some of the most high-profile roll calls taken by senators this year.

“The procedural votes may be more important than the vote on removal or acquittal. Because what will matter more to voters than where a senator lands is how he or she got there,” said Geoff Garin, a Democratic pollster for Hart Research. “So if Susan Collins or any of the other Republicans vote for acquittal and the takeaway for voters is this is a political or partisan vote on an important issue, that will have a long lasting impact.”

Senate Republicans argue that they should rely on the same set of evidence presented in the House, at least for the start, and let the Senate decide on whether to bring in more witnesses after hearing presentations from House managers and the president’s defense.

The GOP has also cautioned Democratic colleagues who are calling for testimony from Mulvaney and Bolton that they will respond with votes to bring in Hunter Biden, Vice President Joe Biden’s son.

“We’re not foreclosing additional witnesses,” said Sen. John Cornyn (R-Texas), who is up for re-election.

Democrats have misjudged the politics of McConnell’s hardline positioning before. In 2016, the party designed a political campaign around the GOP’s blockade of Merrick Garland’s nomination to the Supreme Court.

But their push went nowhere and eventually Democrats’ dropped their rallying cry of “Do Your Job.” Republicans, meanwhile, credited the vacancy with winning them the presidency and holding the Senate. And some in the GOP see the impeachment trial’s politics playing out in a similar fashion.

“The more the American people learn about the impeachment process, I think the more they come to appreciate that the Senate is not in charge of impeachment,” said Sen. Todd Young (R-Ind.), who chairs the Senate GOP’s campaign arm. “They’re starting to understand that there are a lot of games being played here.”

But perhaps the biggest difference between 2016 and 2020 is that Trump now enjoys three years of Republicans almost always siding with him on the Senate floor. And Democrats believe no issue will highlight that more than the choice of whether to hear new evidence from witnesses at the trial to remove the president from office.

“This is an opportunity for Republicans who stake a claim to moderation and independence back home to put their money where their mouth is,” said Sen. Brian Schatz (D-Hawaii). “This is a true binary test: Of whether or not you are all in for Trump, or whether you will occasionally demonstrate that you’re going to use your own mind and your own spine.”