Political observers and politicians from both major U.S. parties reacted with disgust to Monday鈥檚 press conference between U.S. President Donald Trump and Russian President Vladimir Putin in Helsinki, during which Trump openly questioned his own administration鈥檚 conclusion that Russia tried to undermine the 2016 U.S. presidential election.

"I don't see any reason why Russia would interfere in the 2016 election," Trump told astonished reporters.

University of Mary Washington professor Steve Farnsworth called the comments a 鈥渂ig win for Vladimir Putin,鈥� considering that on Friday for interfering in the 2016 U.S. election.

Farnsworth said the meeting should never have happened in the first place, likening it to U.S. President Franklin Delano Roosevelt meeting with Japan鈥檚 Emperor Hirohito after the 1941 attack on Pearl Harbor.

鈥淵ou are rewarding a dictatorship that鈥檚 occupying other countries in Europe, that has done more than almost any country in the world to manipulate the American electoral process,鈥� Farnsworth told 麻豆影视 Channel.

Farnsworth said that America fought the Cold War with Soviet Russia based on the idea that America鈥檚 positon in the world is 鈥渆nhanced by the promotion of free societies and democratic societies.鈥�

鈥淚t is really astonishing that that huge advantage that America has had -- an advantage that has been used by Republican and Democratic presidents (alike) in the fighting against authoritarianism for 80 years -- is simply walked away from by President Trump,鈥� Farnsworth added.

Republican strategist Cory Crowley said that Trump showed 鈥渄isgusting鈥� weakness and pointed out that Trump had frequently criticized his predecessor, Barack Obama, for his perceived weakness on the global stage.

However, Crowley said the Democrats will have trouble convincing the American public of just how damaging the press conference was, because 鈥渘either party and very few people in Washington have any credibility鈥� on foreign policy. In his view, Obama failed to project U.S. strength abroad.

鈥淚f the Republicans remain quiet, there鈥檚 going to be nobody left with integrity,鈥� Crowley said.

Crowley added that Republican Sen. John McCain is 鈥渙ne of very few people who can speak with credibility in this situation.鈥�

McCain: Trump 鈥榓based鈥� himself before a 鈥榯yrant鈥�

McCain, who lost to Obama in 2008, called the press conference 鈥渙ne of the most disgraceful performances by an American president in memory.鈥�

鈥淧resident Trump proved not only unable, but unwilling to stand up to Putin,鈥� 鈥淗e and Putin seemed to be speaking from the same script as the president made a conscious choice to defend a tyrant against the fair questions of a free press, and to grant Putin an uncontested platform to spew propaganda and lies to the world.鈥�

鈥淣o prior president has ever abased himself more abjectly before a tyrant,鈥� McCain went on.

鈥淣ot only did President Trump fail to speak the truth about an adversary; but speaking for America to the world, our president failed to defend all that makes us who we are鈥攁 republic of free people dedicated to the cause of liberty at home and abroad,鈥� he added.

Former Florida governor Jeb Bush retweeted McCain鈥檚 statement, as did Democratic New York Sen. Chuck Schumer.

Schumer: 鈥楾houghtless, dangerous, and weak.鈥�

Schumer stated on Twitter that 鈥淚n the entire history of our country, Americans have never seen a president of the United States support an American adversary the way (Trump) has supported President Putin.鈥� He called Trump鈥檚 actions 鈥渢houghtless, dangerous, and weak.鈥�

Meanwhile, top Republican Paul Ryan, Speaker of the House of Representatives, said in a statement that there is 鈥渘o question that Russia interfered in our election and continues to undermine our democracy.鈥�

鈥淭he president must appreciate that Russia is not our ally,鈥� the Wisconsin Congressman went on. 鈥淭here is no moral equivalence between the United States and Russia, which remains hostile to our most basic values.鈥�

Sen. Flake: 鈥楾his is shameful鈥�

Arizona Republican Sen. Jeff Flake, a frequent critic of Trump who has said he will not seek re-election, called the press conference 鈥渟hameful.鈥�

鈥淚 never thought I would see the day when our American President would stand on the stage with the Russian President and place blame on the United States for Russian aggression,鈥� Flake tweeted.

Sen. Corker: 鈥楪ood day for Putin鈥�

Sen. Bob Corker of Tennessee, chairman of the Senate Foreign Relations Committee, called it a 鈥渧ery good day for President Putin."

Corker said Trump seems to care more 鈥渁bout how a leader treats him personally鈥� than pushing back against meddling in the election.

Paul: 鈥楾rump derangement syndrome鈥�

Republican Sen. Rand Paul seemed to defend Trump鈥檚 approach to Russia.

The Kentucky senator told The Associated Press that he believes it's important for the U.S. to keep an open dialogue with its adversaries.

Paul also said that lawmakers and former intelligence officials criticizing the U.S. president are experiencing "Trump derangement syndrome."

Coats: 鈥榃e have been clear鈥�

Dan Coats, the United States Director of National Intelligence, saying the intelligence community provides 鈥渇act-based assessments鈥� to the president.

鈥淲e have been clear in our assessments of Russian meddling in the 2016 election and their ongoing, pervasive efforts to undermine our democracy, and we will continue to provide unvarnished and objective intelligence in support of our national security,鈥� Coats added.

Pelosi: 鈥榃hat do the Russians have on Trump?鈥�

Democratic Leader of the House of Representatives Nancy Pelosi said on Twitter that she finds herself asking, 鈥渨hat do the Russians have on (Trump) personally, financially, & politically?鈥�

鈥淭he answer to that question is that only thing that explains his behavior & his refusal to stand up to Putin,鈥� she added.

Sanders: 鈥楶athetic performance鈥�

Vermont Sen. Bernie Sanders wrote on Twitter: 鈥淢illions of Americans have risked their lives to defend our democracy. What would those brave men and women think if they saw President Trump's pathetic performance today?鈥�

Harris: 鈥淒isgraceful鈥�

Calfornia Sen. Kamala Harris wrote on Twitter: 鈥淭rump flattered Putin who attacked our democracy and insulted the brave men and women of our Intelligence Community. It is disgraceful.鈥�

With files from The Associated Press