Kentucky Sen. Rand Paul painted himself an outsider and a populist as he announced his campaign for the presidency.
"I am running for president to return our country to the principles of liberty and limited government," a quote attributed to Paul said on his site Tuesday morning.
The Republican politician launched his campaign in a midday speech on Tuesday in Louisville, Kentucky, in which he appealed for a "new way" in America—a way, he said, that works against prevailing D.C. practices.
"I have a message. A message that is loud and clear and does not mince words: We have come to take our country back," Paul said at the outset out of the event.
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Paul's entrance into the GOP primary follows Texas Sen. Ted Cruz, who announced in March that he is running. The field is expected to be crowded, however, and candidates will be competing hard for constituencies ranging from the Christian right to traditional Wall Street Republicans.
For his part, the slogan on Paul's website homepage asks supporters to "defeat the Washington machine."
"The Washington machine that gobbles up our freedoms and invades every nook and cranny of our lives must be stopped," he said.
He continued on that theme, pointing to the very nature of modern American politics for many of the country's woes.
"It seems to me that both parties and the entire political system are to blame, Paul said, citing debt increases under both Republican President George W. Bush and Democratic President Barack Obama.
In addition to that criticism, Paul took a decidedly populist tone in his Tuesday speech, remarking that "Washington is horribly broken, I fear it can't be fixed from within—we the people must rise up and demand action." Paul has served in the Senate since 2011, but is hardly a career politician, having worked as a physician before running for office.
In addition to domestic issues like economic growth and the federal budget, Paul addressed geopolitical issues, including calling out "radical Islam" as America's chief enemy.
The son of libertarian icon and former Texas congressman Ron Paul, the Kentucky Senator has worked to expand his appeal to a broader swath of the Republican Party.
The firebrand who wants to scale back the authority of the Federal Reserve has been quietly courting Wall Street donors. Paul, who mounted a 13-hour filibuster to call attention to the United States' use of drones, recently proposed a boost to military spending.
And the 52-year-old former eye surgeon who harnessed the anti-establishment energy of the tea party movement has been raising money for fellow Republicans, at times upsetting the grass-roots activists who have made him a national figure.
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On many issues, Paul's positions aren't different from mainstream Republicans. He opposes Obamacare and abortion and favors cutting taxes and spending.
But his criticism of the Federal Reserve has spooked some in the party's business-friendly wing, and his proposal to balance the federal budget within five years is dramatic even by the standards of the anti-spending Republican Party.
Paul starts the campaign in the second tier of GOP candidates, drawing the support of 8.4 percent of Republicans, according to a March Reuters/Ipsos tracking poll.
That puts him behind former Florida Gov. Jeb Bush, Wisconsin Gov. Scott Walker and former Arkansas Gov. Mike Huckabee, and in a statistical tie with four other candidates—Cruz, New Jersey Gov. Chris Christie, neurosurgeon Ben Carson and Florida Sen. Marco Rubio.
—Reuters contributed to this report.
Correction: This version corrects Marco Rubio's title and the location of Paul's scheduled announcement.