Campaigning in the crucial battleground state of Florida, Donald Trump has bashed Democrats and Republicans alike, from Hillary Clinton to former Republican presidential nominee Mitt Romney on the right.
Addressing a crowd of thousands at the Tampa Convention Centre on Saturday, Trump tore into "Crooked Hillary," as he calls his likely general election opponent, over her use of a private email server while secretary of state.
He called Romney a "stone, cold loser" for not backing him as the presumptive Republican nominee.
Trump said the Republican Party "has got to get their act together, come together to win." He slammed Republicans in the US Senate who oppose his candidacy.
He spoke confidently of his own ability to win the presidency, but warned that Republican seats in the House and Senate could be at risk if Republicans don't rally behind him.
"The Republican party has to be tough and smart," he said. "If not, I'm gonna win but a lot of other people are not."
Trump was introduced by Florida's top Republicans, Governor Rick Scott and Attorney General Pam Bondi.
"Donald Trump is hopeful," said Scott, whose support of Trump has generated running mate speculation. "The opposite of hopeful is Hillary Clinton."
Trump, at one point, asked the crowd to shout out names of potential running mates. Former House Speaker Newt Gingrich, Alabama Senator Jeff Sessions and former Secretary of State Condoleezza Rice, were among the names he repeated.
"This is fun," bellowed Trump. "We have a lot of good people."
Toward the end of his speech, Trump supporters broke into a chorus of "Happy Birthday." He turns 70-years old on June 14.
As his supporters began singing, Trump laughed and said "I don't want to hear about it."
He said he's "very torn" about the birthday, but added: "I feel like I'm 35. That's the good news."
The Tampa rally is Trump's second since the end of the primary season. He is scheduled to hold another rally later on Saturday in Pittsburgh.
