As a result, Smith adviser Mark Harris, who managed Sen. Pat Toomey's successful Senate campaign in 2010, wrote a memo last week arguing that his candidate is the clear frontrunner in the race. Harris's argument is hard to quibble with, considering Smith's current financial advantage. He is the only candidate already running television ads in a race without any particularly well-known candidates. That said, Smith brings his own vulnerabilities to the contest. Like Welch, he enters the race as an unfamiliar name -- but a constant stream of TV ads could fix that. And Smith has his own history as a member of the Democratic Party. While opponents will try to challenge his conservatism as a result of this, Smith will have an easier time dodging the charge than Welch. He has a long history of donations to conservative candidates and isn't saddled with Welch's controversial vote for Obama. The Conservative Alternative: While his chances of actually winning the nomination are a long-shot, former state Rep. Sam Rohrer will remain relevant in the primary campaign because of his popularity with grassroots conservatives. Rohrer ran against Corbett in the 2010 gubernatorial primary, finishing with 31 percent of the vote. Thanks to that statewide run, he enters the Senate race with a built-in core group of supporters. Rohrer also has an obvious message to sell to the state's Republican voters. A favorite of many tea party groups in the state, Rohrer likely will argue that he is the only reliable conservative with a realistic shot of winning the nomination. This case becomes easier to make if his two main opponents are Welch and Smith, both of whom have past ties to the Democratic Party. But Rohrer's upside is limited by what will likely be a severe disadvantage in fundraising. Smith and, to a lesser extent, Welch (he loaned his campaign $1 million) already have demonstrated a willingness to spend their own money on their campaigns. Rohrer, who finished last year with less than $70,000 in the bank, will struggle to keep up with his deep-pocketed rivals, making a primary victory very unlikely.