Hillary Clinton said President Trump is waging an "assault on our democracy," and called on people to vote for Democrats in the midterm elections to help protect it.

“As citizens, that’s our most important charge,” she wrote in an essay published by The Atlantic. “And right now, our democracy is in crisis … [O]ur democratic institutions and traditions are under siege. We need to do everything we can to fight back. There’s not a moment to lose.”

"I don’t use the word crisis lightly," she warned. "There are no tanks in the streets. The administration’s malevolence may be constrained on some fronts — for now — by its incompetence. But our democratic institutions and traditions are under siege. We need to do everything we can to fight back. There’s not a moment to lose."

[Related: Obama unloads on Trump, warns of 'dangerous times' in fiery speech]

Clinton called for a "massive" turnout in the 2018 midterms, which she said could help provide more congressional oversight of Trump's White House.

She wrote that Trump is undermining U.S. democracy in five ways: His “assault on the rule of law,” his unwillingness to protect the legitimacy of U.S. elections, his “war on truth and reason,” his “breathtaking corruption,” and by undermining national unity.

But she said Trump is only continuing down a path that other Republicans have followed for years.

“We should be clear about this: The increasing radicalism and irresponsibility of the Republican Party, including decades of demeaning government, demonizing Democrats, and debasing norms, is what gave us Donald Trump," she wrote. "Whether it was abusing the filibuster and stealing a Supreme Court seat, gerrymandering congressional districts to disenfranchise African-Americans, or muzzling government climate scientists, Republicans were undermining American democracy long before Trump made it to the Oval Office."

Clinton proposed other ways the U.S. might avoid electing another candidate like Trump. For example, she said all future presidential candidates should be required by law to release their tax returns, something Trump did not do. She said students should be taught civics in school, and economic reforms aimed at reducing inequality and “the unchecked power of corporations.”

She also made some suggestions about voting, including the elimination of the Electoral College system that gave Trump the win over Clinton even though she won the popular vote.

“You won’t be surprised to hear that I passionately believe it’s time to abolish the Electoral College,” she wrote. Clinton called for paper ballot backups, vote audits and more coordination between federal state and local officials on cybersecurity to boost the security of the voting system, and asked Congress to “repair the damage the Supreme Court did to the Voting Rights Act by restoring the full protections that voters need and deserve."

Clinton’s essay was adapted from the afterword of the paperback edition of her memoir, What Happened, which is set to published this week.