Mitt Romney, the 2012 Republican presidential nominee and former governor of Massachusetts, officially announced Friday morning that he is running for the Senate seat being vacated by seven-term GOP Sen. Orrin Hatch of Utah.Romney tweeted a video announcement, after delaying a planned launch on Thursday in the wake of the deadly mass school shooting in Parkland, Fla.Romney, who spoke out forcefully against Trump during the 2016 presidential campaign, blasted Washington and took veiled swipes at the president in the video."Utah welcomes legal immigrants from around the world," Romney says. "Washington sends immigrants a message of exclusion. And on Utah's Capitol Hill, people treat one another with respect."A Sen. Romney would add yet another layer of drama to Washington. During the 2016 campaign, Romney called Trump a "phony" and a "fraud." Trump, who tried to persuade Hatch to run for re-election, responded hotly during the campaign, saying Romney "would have dropped to his knees" for Trump's endorsement in 2012.From afar, Romney has been critical of Trump's policies. Now, he has the opportunity to do it up close — and with a likely national television spotlight, if he seeks it out, that will beam him right into the White House, in plain view of this president, a habitual cable-news watcher.A run not without criticism locallyRomney's announcement was widely anticipated after Hatch, the longest-serving Republican senator in U.S. history, said in early January that he was calling it quits after 42 years of service. Hatch told The Salt Lake Tribune that he was urging Romney to run.Romney is seen as an early favorite to win the Senate seat, but not every Republican in the state is happy he is running. He is facing criticism from, of all people, the state Republican Party chairman."I think he's keeping out candidates that I think would be a better fit for Utah," Rob Anderson told the Tribune, "because, let's face it, Mitt Romney doesn't live here, his kids weren't born here, he doesn't shop here."Romney was governor of Massachusetts, where he was registered to vote and ran his private investment firm, Bain Capital. He also has lived most of the time at his beachside home in San Diego.But Romney also owns a home in Park City, Utah, and has close ties to the leadership of the Church of Jesus Christ of Latter-day Saints. In addition to serving as a missionary for the church in France in the 1960s, he has held several leadership positions, including lay bishop. He is probably the most prominent Mormon in the country.Perhaps to combat the carpetbagger critique — and to assure voters of his focus in running for the Senate — he mentions Utah by name 14 times in his announcement video. Another potential critique is that the 70-year-old might use his potential national platform to run for president again in two or six years.Bolstering his case to run, Romney has consistently been regarded as one of the most popular politicians in the state. A pollfrom November, for example, showed him with a 69 percent approval rating. Early Senate race polling has shown Romney comfortably ahead in hypothetical matchups against Democrat Jenny Wilson, who currently sits on the Salt Lake County Council.How he got hereRomney ran for the Senate in Massachusetts in 1994, losing to Democrat Ted Kennedy. He was elected as the state's governor in 2002.In the interim, Romney stepped in to turn around the scandal-plagued 2002 Salt Lake Winter Olympics, which vaulted his reputation in Utah.His connection to his church has also been key. In fact, that connection goes back generations. Romney's great-great-grandfather Miles Romney was a Mormon pioneer, who settled in Utah in the 19th century and designed the famed St. George Tabernacle.In 2012, Romney won nearly 73 percent share of the vote in Utah, soundly defeating President Barack Obama there by 48 points. Contrast that with the 2016 presidential race. While Donald Trump won Utah, he only received 46 percent of the vote.Many Utahans, fueled by their growing unease with Trump's divisive rhetoric, instead cast their vote for Evan McMullin, a third-party candidate and a Mormon, who got 21 percent.Romney's stature in the GOP and history of criticizing Trump create the potential for a powerful Trump Republican critic coming to Washington as others like Sen. Jeff Flake of Arizona retire.Here's how NPR's Mara Liasson envisioned the scenario playing out in a report from December: