The liberal hope that President Donald Trump could be impeached is no longer a mere daydream. As The New York Times revealed Tuesday, Donald Trump Jr. met last June with a Kremlin-connected lawyer for the explicit purpose of obtaining purported dirt on Hillary Clinton that was dug up as part of the Russian government’s effort to help his father’s campaign. Robert Goldstone, the British publicist who arranged the meeting, wrote in an email to Trump Jr. that the Russians had “offered to provide the Trump campaign with some official documents and information that would incriminate Hillary and her dealings with Russia and would be very useful to your father. This is obviously very high level and sensitive information but is part of Russia and its government’s support for Mr. Trump.” He later added, “If it’s what you say I love it especially later in the summer.”

This is by far the best evidence of collusion between the Trump campaign and Russia, entangling not only the other parties involved—Trump’s son-in-law Jared Kushner and campaign manager Paul Manafort were later looped into the email thread—as well as those discussed in the exchange, including the president himself. Yet if the path toward impeachment is becoming easier to imagine, there still remain formidable political hurdles to such an outcome because of the Republican Party’s grip on the legislative branch. The revelations about Donald Jr. may force Democrats to answer a question they have long avoided: Should they make the Republican Party, especially its leadership in Congress, complicit in Trump’s ever-widening Russia scandal?

The Democrats, as the minority party, need the Republicans’ help in investigating Trump and keeping him in check. Taking down Trump would require even more, and unrealistic, cooperation. Impeachment requires a majority vote in the House of Representatives, after which two-thirds of the Senate must vote him guilty. So let’s assume that won’t happen before next fall’s midterm elections. Even if the Democrats won the House of Representatives, which is by no means a sure thing, they are unlikely to accomplish the same in the Senate, where the 2018 map heavily favors Republicans. So Senate Democrats would still need to secure roughly 20 Republican votes for a guilty verdict.

On the other hand, the Democrats could choose not to work with the Republicans on removing Trump, and instead tarnish the party for enabling the president. The Russia scandal implicates not just Trump but the GOP itself, which has been guilty of aiding and abetting the president by undermining the Russia investigation and offering post-facto justifications.

Mitch McConnell is a prime example of Republican complicity. When the intelligence community first concluded last August that the Russian government was intent on interfering in the election to hurt Clinton and help Trump, President Barack Obama sought “bipartisan support from congressional leaders for a statement condemning Moscow and urging states to accept federal help,” according to The Washington Post. This bipartisan effort failed because, in a meeting of top congressional leaders in early September, “Republicans resisted, arguing that to warn the public that the election was under attack would further Russia’s aim of sapping confidence in the system. Senate Majority Leader Mitch McConnell (R-Ky.) went further, officials said, voicing skepticism that the underlying intelligence truly supported the White House’s claims.”

Republicans have continued to run interference for Trump since he won the election. Congressman Devin Nunes, the chair of the powerful House Intelligence Committee, in February referred to the Russia investigation as a “witch hunt,” adding that “what I’ve been told by many folks is that there’s nothing there.” During the Senate testimony of James Comey, Republicans seemed as eager to discredit the fired FBI director, and downplay the entire scandal, than listen to his account of the president trying to obstruct justice. “The only thing that’s never been leaked,” Senator Marco Rubio said at the time, “is the fact that the president has never been under investigation.” After the testimony, House Speaker Paul Ryan defended Trump by saying he’s “new” to politics.

The Republican reaction to the latest news is telling. Utah Senator Orrin Hatch said Trump Jr. is “a very nice young man” and said of the emails story, “I think that’s overblown.” Senator Thom Tillis of North Carolina said the emails are “the very thing we should not be distracted by,” while New York Congressman Lee Zeldin described them as a “nothing burger.” Other Republicans, including McConnell, have been more muted. They didn’t explicitly defend the president, but didn’t sound alarmed either.

The Washington Post’s Greg Sargent argued Tuesday that “congressional Republicans continue to enable Trump’s ongoing erosion of our democracy on multiple fronts. Now, in light of Trump Jr.’s emails, their refusal to take the Russian assault seriously enough during the campaign takes on added meaning and demands more scrutiny in a big way.” Such scrutiny is long overdue, but it doesn’t solve Democrats’ political dilemma. They have every right to tie the Republicans to the Trump campaign’s collusion, and it would energize the base ahead of the midterms. Such a move will come at a cost, though, making it all the more difficult to get the Republican Congress to hold Trump to account.

But if the events of the past year have taught us anything, it’s the folly of expecting elected Republicans to do the right thing when it comes to Trump, rather than what’s politically expedient. Trump Jr.’s highly damaging emails have handed Democrats the leverage they’ve long sought in the Russia scandal. They should take advantage of it by making a final offer to the Republicans to abandon their support for Trump, or suffer the consequences. If the GOP steps up their investigation, they might damage their short-term political prospects—assuming they can pass any major legislation, which is not a given. But they’ll be acting in their own long-term interest, by distancing themselves from an increasingly unpopular president, and they’ll finally be doing the right thing to preserve what’s left of America’s democratic norms. But if the Republicans continue to drag their feet, then they must be treated no better than Trump’s other unsavory accomplices, and suffer the electoral consequences.