By now, comparisons between Watergate and Richard Nixon and the Russia investigation and Donald Trump have become stale.

Soon after Trump entered the White House, his national security adviser Michael Flynn was forced to resign after getting caught up in the investigation into Russian meddling in the last year’s election.

Then his attorney general, Jeff Sessions, recused himself from the probe after it was revealed he had met with one of the Russian officials at the center of the investigation.

Concerns escalated after the president fired FBI Director James B. Comey in May, drawing comparisons to Nixon’s “Saturday Night Massacre,” when he fired Watergate special prosecutor Archibald Cox.

The cloud hanging over Trump’s first five months in office has motivated many upstart Democrats to consider running for Congress, both in special elections this year, and in the 2018 midterms. That enthusiasm has drawn comparisons to 1974, when Democrats won 49 House seats and 5 Senate seats in the first election after the Watergate scandal and Nixon’s resignation.