"By proceeding with your invalid impeachment, you are violating your oaths of office, you are breaking your allegiance to the Constitution, and you are declaring open war on American Democracy," Trump said in the Tuesday open letter to Pelosi, who as House Speaker has pushed for an impeachment inquiry into Trump.
"More due process was afforded to those accused in the Salem Witch Trials," Trump declares in the five-page letter.
Trump says the charge of abuse of power in the articles of impeachment the House plans to vote on Wednesday is "a completely disingenuous, meritless, and baseless invention of your imagination."
"You are turning a policy disagreement between two branches of government into an impeachable offense - it is no more legitimate than the Executive Branch charging members of Congress with crimes for the lawful exercise of legislative power," Trump continued.
Since October, several House committees have investigated Trump's July 25 phone call with Ukrainian President Volodymyr Zelenskyy, the pivotal event of a larger movement to press Kiev to open an investigation into former US Vice President Joe Biden and his son, Hunter Biden. House Democrats argue that Trump illegally forced Zelenskyy's hand with a "quid pro quo" agreement by withholding military aid until the probe was opened.
Trump further disputes the second impeachment charge, "obstruction of Congress," calling it "preposterous and dangerous."
"Everyone, you included, knows what is really happening," Trump continues, arguing the Democratic Party has "never recovered" from its defeat in the 2016 election, in which Trump beat out Democratic candidate Hillary Clinton to become president. "You are unwilling and unable to accept the verdict issued at the ballot box during the great election of 2016. So you have spent three straight years attempting to overturn the will of the American people and nullify their votes. You view democracy as your enemy!"
"You are the ones interfering in America's elections. You are the ones subverting America's Democracy. You are the ones Obstructing Justice. You are the ones bringing pain and suffering to our republic for your own selfish personal, political, and partisan gain," the letter continues.
The president goes on to note that if the Democrats "truly cared about freedom and liberty for our nation," they would be dedicating their efforts to "exposing the full truth concerning the FBI's horrifying abuses of power before, during, and after the 2016 election."
A report by the Department of Justice Inspector General issued earlier this month found extensive failures in the FBI to follow proper procedures when applying for surveillance warrants with the Foreign Intelligence Surveillance Court to monitor four Trump campaign advisers in 2016, but not political bias in that process. However, a much larger investigation, headed by US Attorney John Durham at the behest of the attorney general, has yet to report on its findings about the origins of the Russiagate investigation. Durham did, however, issue a statement saying he did not agree with the IG's findings about a lack of political bias.