Poll: Obama opens 10-point lead over Romney

President Obama has opened up his largest lead of the campaign, according to a Rasmussen's daily tracking poll, taking a 10-point lead in a hypothetical matchup against Republican front-runner Mitt Romney.

Obama is the choice of 50 percent of voters in the Rasmussen poll, while Romney wins 40 percent of those likely to head to the polls. It's the first time Obama has won at least half of voters in a direct matchup against Romney.

Rasmussen credited Obama's improvement in the polls to positive economic news.

"The president’s job approval ratings for handling the economy have improved lately, and it’s no coincidence that perceptions of how he’s handling the economy have improved as well," Rasmussen wrote in a blog post accompanying the results. "The economy remains the most important issue of Election 2012, and voters are a bit more likely to trust Republicans than Democrats on handling the economy."

Rick Santorum, surging off a trio of surprising wins Tuesday night, is now outperforming Romney in hypothetical one-on-one matchups with the president. Obama leads Santorum by just 4 percentage points, holding a 46 percent to 42 percent advantage.

Those numbers will be of some concern to the Romney team, after their candidate has struggled to put away the Republican nomination. Santorum, speaking Friday at the Conservative Political Action Conference in Washington, argued that Romney's tepid support among conservatives would hurt in a general election.

"We always talk about appealing to moderates," Santorum said. "Why would an undecided voter vote for the candidate that the party's not excited about? We need conservatives to rally for a conservative, to pull with that excitement moderate voters, and to defeat Barack Obama in the fall."

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