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.”