In it, the ex-president attacked Senator Mitch McConnell for the defeats of Kelly Loeffler and David Perdue in the January special elections that handed control of the Senate to Democrats.
Mr Trump, who also lost the state to Joe Biden last November, blamed Mr McConnell for only offering $600 stimulus checks while his opponents campaigned on payments of $2,000.
The former president said that the first reason the Senators lost their seats was the anger many GOP voters in the state felt towards Republican leadership there and Governor Brian Kemp.
Then he turned his anger on Mr McConnell, who recently voted to acquit Mr Trump at the end of his historic second impeachment trial in the Senate – but then delivered a stunning rebuke of the former president saying there was no doubt he bore responsibility for the insurrection.
Watch: Illinois congressman pressures Republicans to leave Trump behind
“Second, Senator Mitch McConnell’s refusal to go above $600 per person on the stimulus check payments when the two Democrat opponents were touting $2,000 per person in ad after ad,” wrote Mr Trump.
“This latter point was used against our Senators and the $2,000 will be approved anyway by the Democrats who bought the Georgia election — and McConnell let them do it!
“Even more stupidly, the (NRSC) spent millions of dollars on ineffective TV ads starring Mitch McConnell, the most unpopular politician in the country, who only won in Kentucky because President Trump endorsed him. He would have lost badly without this endorsement.”
Mr Trump also blasted the Rupert Murdoch-owned Wall Street Journal and its opinion page, where the editorial board recently published an article on Mr Trump, asking “If he was so great politically for the GOP, why is the party now out of power?”
“The Wall Street Journal editorial page continues, knowingly, to fight for globalist policies, such as bad trade deals, open borders, and endless wars that favour other countries and sell out our great American workers, and they fight for RINOS that have so badly hurt the Republican Party,” replied Mr Trump in his statement.
Mr Trump and his MAGA supporters use the term “RINOS” as shorthand for “Republicans in name only”, or those conservatives who do not support the ex-president.
“That’s where they are and that’s where they will always be. Fortunately nobody cares much about The Wall Street Journal editorial anymore. They have lost great credibility,” he added.
In his statement Mr Trump noted that many Republicans were angry that Mr Kemp had failed to “stand up to Stacey Abrams”, the Democratic activist credited with turning Georgia blue, and the Consent Decree that “virtually eliminated signature verification requirements across the state.”
That claim was quickly debunked on social media, with observers pointing out that the decree just standardised signature match and ballot cure procedures for elections in the state.
The statement was a relatively rare intervention by Mr Trump, who has been banned from Twitter – previously his favourite form of communication – and other social media sites for fear he would incite his followers to violence.