The new numbers are the highest total favorability numbers the poll has reported for Toomey.

Twenty-three percent said they have a favorable opinion of the senator and 12 percent said they have a "strongly" favorable opinion of Toomey. Eleven percent said they have an unfavorable or somewhat unfavorable opinion of the senator.

In a February poll, Franklin & Marshall found Toomey's total favorability at 26 percent.

Toomey has been enjoying increasing approval numbers in polls taken after he co-authored legislation with Democratic Sen. Joe ManchinJoseph (Joe) ManchinTrump rips Dems a day ahead of key White House meeting Senate panel moves forward with bill to roll back Dodd-Frank Wealthy outsiders threaten to shake up GOP Senate primaries MORE (W.Va.) to expand background checks for all gun show and online sales. While the measure failed to get the 60 votes it needed to pass the Senate, their efforts were hailed by pro-gun control advocates.

Polling since the vote has shown lowered approval ratings for lawmakers who voted against the background check legislation, with proponents of the Manchin-Toomey measure enjoying higher positive ratings. A Quinnipiac University poll released in late April found Toomey's approval rating in his home state had jumped to 48 percent.

Additionally, the Franklin & Marshall poll found that 89 percent of those surveyed strongly or somewhat favor requiring background checks for gun sales, with 9 percent opposing.

The Franklin & Marshall poll was conducted among 526 registered Pennsylvania voters. Of those surveyed, 265 identified as Democrats, and 196 identified as Republicans. The poll had a sample error of 4 percentage points.