Here's the letter Donald Trump wrote to Harry Reid in 2010

Outgoing Senate Minority Leader Harry Reid (D-Nev.) had just won re-election against Republican competitor Sharron Angle in 2010 when he received a letter from now President-elect Donald Trump, who had donated $4,800 to the Nevada lawmaker's campaign.

"Congratulations," the short memo began. "You are amazing!"

Reid's office shared the letter with BuzzFeed News following a tweet from Trump calling incoming Senate Minority Leader Chuck Schumer (D-N.Y.) "far smarter" than Reid.

From 1996 to 2010, Trump and his family donated thousands of dollars to Schumer. The billionaire businessman has defended his contributions by saying donating to a Republican in New York City would be "stupid" because they get only "1 percent of the vote."