WASHINGTON (AP) — Texas Senator Ted Cruz, one of the Republican Party’s most conservative members, announced early Monday he is running for the party’s 2016 presidential nomination, making him the first among what is expected to be a crowded field of White House hopefuls to officially enter the race.

Elected to the Senate in 2012, Cruz quickly established himself as an uncompromising conservative willing to take on Democrats and fellow Republicans alike.

He won praise from ultraconservative tea party activists in 2013 for leading a 16-day government shutdown in an unsuccessful drive to repeal President Barack Obama’s health care overhaul. But he has been scorned at times by leading members of his own party, with fellow senator and former presidential candidate John McCain once labeling him a “wacko bird.”

Cruz, 44, announced his candidacy on Twitter just after midnight, several hours before the official launch at Liberty University, the Virginia college founded by the late Reverend Jerry Falwell. The setting indicates Cruz plans an aggressive courtship of cultural conservatives and young voters.

“I’m running for president and I hope to earn your support!” he tweeted. In an early preview of his campaign message, he says in an accompanying video that “it is going to take a new generation of courageous conservatives to make America great again.”

Cruz’s popularity within the right-wing base could give him shine in the primary, a state-by-state process dominated by the most conservative Republican voters. But his tense relationship with the Republican Party establishment complicates his path to the nomination. And if he makes it to the general election, he would have a hard time winning over moderate Republicans and independent voters.

Several other Republicans are expected to enter the race in the coming weeks, including former Florida Governor Jeb Bush, Wisconsin Governor Scott Walker and two Senate colleagues, Kentucky’s Rand Paul and Florida’s Marco Rubio. None is considered a heavy favorite, though Bush had been getting the most attention in recent weeks as he takes aggressive steps toward launching his candidacy.

Whoever wins the Republican nomination would likely face former secretary of state Hillary Rodham Clinton, the front-runner for the Democratic nod who is expected to soon launch her campaign.

Cruz, the son of an American mother and Cuban-born father, is seeking to be the nation’s first Hispanic president.

The senator was born in Canada, but two lawyers who represented presidents from both parties at the Supreme Court recently wrote in the Harvard Law Review that Cruz meets the constitutional requirement to run.

Cruz is set to release a book this summer that he has said would reflect themes of his White House campaign. In a recent Associated Press interview, he said he wants to counter the “caricatures” of the right as “stupid,” ”evil” or “crazy.”

“The image created in the mainstream media does not comply with the facts,” said Cruz, who does not believe in climate change.

Cruz continues to be a leading voice for repeal of the Affordable Care Act, widely known as Obamacare. He promises to abolish the tax-collecting Internal Revenue Service, scrap the Education Department and curtail federal regulators, likening them to locusts.

He also is a staunch social conservative who opposes both gay marriage and abortion rights. His father, Rafael, is an outspoken evangelical pastor.

On foreign policy, Cruz was among 47 Republican senators who signed a letter to Iran’s supreme leader warning that any nuclear deal that is struck with the Obama administration and five other world powers could become null and void after the 2016 election when the current president leaves the White House. Cruz is a strong backer of Israel.

He also is opposed to Obama’s executive action to ease deportations of millions of immigrants in the country illegally and to the White House opening to communist Cuba, his father’s homeland.