Republicans appear to be much more optimistic about the upcoming presidential race compared to the two previous campaign cycles.

Pew Research Center data shows the favorability of the Republican lineup has increased while favorability among Democrats for their party has stagnated.

The survey polled 2,002 people, including 1,497 registered voters, between May 12 and May 18 and found Republicans and Republican-leaning voters have a more positive opinion of the party's lineup. Conversely, Democrats were not as excited about this campaign cycle's Democratic field compared to previous years.

Around 57 percent of Republican voters have an excellent or good opinion of the party's lineup, which continues to grow, and now numbers more than 10 candidates or hopefuls. The Democratic Party only has two candidates so far: Hillary Clinton and Sen. Bernie Sanders.

Among Democrats polled, 54 percent have a positive view of the candidates, which is lower than it was in September 2007. Before the 2008 election, 64 percent of Democratic voters viewed the lineup favorably and held higher percentages than Republicans.

In May 2011, 44 percent of Republicans viewed their candidates in a positive light. In the 2008 election cycle 50 percent saw their candidates favorably. However, the tables have turned.

Republican candidates are enjoying higher positive ratings from their voters, despite having a much wider lineup. The survey questioned respondents about six Republican candidates or potential candidates, including Jeb Bush, Mike Huckabee, Sen. Rand Paul, Sen. Marco Rubio, Sen. Ted Cruz and Gov. Scott Walker.

The most well-known was Bush; however, the brother of former President George W. Bush also had the highest unfavorable rating, around 35 percent. Huckabee won the highest percentage, 54, among Republicans. Bush's and Paul's were around 52 percent.

Polling data shows a trend of stronger support for the GOP lineup among more conservative voters. Liberal and moderate Republican voters view the lineup positively less than 50 percent for most candidates, except Bush who edges over with 51 percent.

Among conservative Republicans Huckabee and Sen. Rubio do the best with 62 and 60 percent favorability, respectively. This data contrasts with one poll taken in New Hampshire earlier in the month. Sen. Rubio, along with Sen. Paul and Bush, had higher positive ratings, ranging between the high fifties and low sixties. Huckabee, on the other hand, was around 10 points lower.

Clinton continues to dominate among Democratic voters but her favorability rating has dropped since 2007 when it soared at 81 percent. It is now 77 percent, still far larger than her Republican opponents. Yet, among the youngest voting group, millenials who could not vote in 2008, she is polling at 65 percent, the lowest for any of the cohorts.

The polling data, though, shows a trend of increased positive opinion among GOP voters of their party's lineup and also shows Republicans remain unsure of who to back. All the numbers show similar favorability percentages for the six contenders mentioned. As the campaign cycle continues, only more Republicans will join the already crowded GOP field.