WASHINGTON – Mitt Romney won both the Michigan and Arizona Republican presidential primaries on Tuesday night, giving him the lion’s share of delegates thus far for the GOP nomination and reestablishing himself as the front-runner in the race.Romney and his challengers face just one other vote, the Washington state caucus on Saturday, before next week’s Super Tuesday contests, when 10 states head to the polls.Romney, who was at one time expected to easily win Michigan since he grew up there and his father was once its governor, edged out only a three-point margin of 41 percent to Santorum’s 38% Tuesday night.Romney, speaking to supporters Tuesday night, acknowledged that the win was modest.“We didn’t win by a lot, but we won by enough and that’s all that counts,” he said.Santorum, for his part, emphasized the inroads made by challenging Romney so strongly.“A month ago, they didn’t know who we are.They do now,” Santorum told his own backers following Tuesday’s vote.Gingrich, who received just 7% of Tuesday’s Michigan vote, spent the day in Georgia focusing on the southern state he once represented in Congress, which his campaign believed he had a better chance of winning than either Michigan or Arizona.Georgia has the most delegates at stake on Tuesday, though Virginia, Tennessee and Ohio also have significant numbers, with the last a key swing state that is often a bellwether for the rest of the country in the general election.Gingrich has long seen the South – home to the one state, South Carolina, that he’s won so far – as his strong suit, and has struggled to stay relevant in the other contests. But the former US speaker of the House is now reported to be receiving another significant cash infusion from casino magnate Sheldon Adelson, who along with his wife has already given upwards of $10 million to his campaign.Meanwhile, the remaining GOP candidate, Ron Paul, has his sites set on the Super Tuesday caucuses in Alaska, North Dakota and Idaho, as well as Washington, which is seen as representing his best possibility of picking up a victory.He received 12% of the Michigan vote and 8% of Arizona’s. Gingrich garnered 16% in Arizona, with Santorum taking 27% and Romney easily prevailing with 47%.Romney has chosen to appear that day at the Washington DC conference of the American Israel Public Affairs Committee (AIPAC), the largest pro-Israel lobby. This year’s attendance is expected to set a record, with well over 10,000 attendees.GOP competitors Rick Santorum, who has posed the most serious challenge to Romney, and Newt Gingrich are also expected to attend the conference at a time when candidates are traditionally making their last pitch to voters at campaign stops.All three candidates have criticized US President Barack Obama, who will address AIPAC on Sunday, for not standing strongly enough with Israel or taking tough enough steps to stymie Iran’s nuclear ambitions – topics that are sure to figure prominently in their speeches.But the primary battle in Arizona, and even more so in Michigan, focused primarily on domestic issues, as the candidates tried to argue that each was the best choice to help economically struggling locales.Values issues also played a role, as Santorum, a Catholic, attacked John F. Kennedy’s campaign speech on the importance of the separation of church and state, delivered to reassure voters that as president he wouldn’t take orders from the Vatican. The move earned him criticism from Gingrich and didn’t help him prevail among Catholics in Michigan, who went for the Mormon Romney 44 to 37.