But winning Tuesday's Texas primary -- an easy feat given he's now running virtually unopposed -- and clinching the Republican nomination is just the first step in what is expected to be a tough five-month campaign for the White House.

If Romney can get just 38% of the popular vote Tuesday in the Lone Star State, he'll reach the 1,144 delegates he needs to secure the GOP nomination at the party's convention in August.

But instead of celebrating with long, tall Texans at his side, the former Massachusetts governor spent the day campaigning and fundraising in Colorado and Nevada, two key swing states in November's general election.

And Romney's political director reportedly conceded there's still a lot of work to do, even if they can finally put the Republican race behind them in Texas Tuesday night.

"That goal is accomplished, but there's a much bigger goal to be accomplished and that's winning the presidency," said Rich Beeson Tuesday. "So while you can take a certain amount of satisfaction and pride for (Romney) and what he's accomplished, he's very resolved to say, 'Our work isn't done.'"

Not only must Romney, a Mormon, win over and energize a Republican base suspicious of his religion and conservative credentials given previous moderate positions he's held, he must also raise a lot of money to compete with the Obama campaign that is expected to break records this year in terms of money spent on a political campaign.

While Romney and Donald Trump were expected to raise $2 million at a Las Vegas fundraiser Tuesday, the candidate instead spent the day distancing himself from The Donald who has again raised the issue of Obama's birthplace.

Most conservatives here don't buy the so-called 'birther' argument that Obama was born in Africa and not Hawaii as his birth certificate suggests, but Trump last week cited a brief biography of Obama from his literary agent that said he was born in Kenya as more evidence Obama is lying.

On Tuesday, the Romney campaign re-affirmed the candidate believes the president was born in the U.S. -- a requirement for a U.S. president -- and said they will keep their campaign focused on the economy and jobs, even as Democrats increasingly attack his business record and try to paint the multi-millionaire as a heartless capitalist.

But polls suggest Americans aren't buying it. In fact, Romney routinely beats Obama when they're asked who they trust to manage the U.S. economy.

Overall, the presidential race appears to be a dead heat with the most recent Rasmussen Reports survey, conducted over the weekend, giving Obama just a one point lead over Romney, 46 to 45%.