Mitt Romney has grabbed a sizable lead among small business voters. (John Moore/GETTY IMAGES)

Main Street has already proved an important battleground in the presidential election. So which candidate is winning the favor of small business owners?

Mitt Romney, and it’s not even close, according to a new poll.

Sixty-one percent of small business owners plan to vote for the Republican challenger, more than double the 26 percent who say they will vote for President Obama, shows a survey released Tuesday by Manta. The president’s numbers have fallen six points since May, while Mitt Romney has picked up four points with business owners. In the latest national polls, the candidates are virtually deadlocked.

Obama still has time to make up ground on Main Street, but he will need a solid performance next month in Charlotte. Forty percent of respondents said their vote could swing based on the small business issues — namely taxes, healthcare and regulations — discussed at the conventions, while one in four said they’re still waiting to see what types of initiatives the candidates outline between now and November.

Manta, which hosts the largest online small business community, polled roughly 2,000 small business owners for the latest report, part of its series of political tracking surveys.

“While it is critical that the presidential candidates address vital small business issues like tax policy and healthcare at the conventions this year, it’s also important that they share concrete examples with the small business community about how proposed initiatives will help them grow their business the rest of year and in the future,” Manta CEO Pamela Springer said in a statement. “With a shaky economy, small businesses are trying to catch up and rely on non-governmental resources to stay in business.”

Romney’s lead among small business owners mirrors his party’s advantage over its political rivals, as 54 percent of respondents believe the Republican Party is the stronger supported of small businesses, while only 19 percent say the same about the Democratic party.

Interestingly enough, Paul Ryan’s selection does not appear to have moved the needle. Manta conducted a smaller poll following Romney’s announcement, in which 5 percent of small business owners said, considering the pick, they now plan to vote for Romney, and 5 percent said they now plan to vote for Obama.

Over the past few months, both presidential candidates have had their stumbles in the eyes of small business owners, the most polarizing being the president’s “you didn’t build that” remark in July. Mitt Romney took heat earlier in the campaign for saying he enjoyed “being able to fire people.”

More recently, the two have drawn a line in the small business sand with their tax policy statements. Mitt Romney has attacked the president for turning his back on business owners by supporting tax increases on the wealthiest Americans, and Democrats have fired back, arguing that very few small business owners would be affected by raising the top rates.

The Republican convention begins Monday, with the Democratic convention one week later.

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Which candidate do you think best understands and supports the needs of small business owners? Please share your thoughts in the comments below.