Vulnerable senators are about to face an onslaught of ads over their failure to do their duty and have a vote on President Obama's Supreme Court nominee. First up? Pennsylvania Senator Pat Toomey.

The Constitutional Responsibility Project released its first ad Friday morning, a 30-second spot which will air in Philadelphia next week. The group's organizer, Stephanie Cutter, said there will be more ads to come, though she declined to release the size of Pennsylvania buy.

The ad comes as senators return home for a week-long recess, during which the Constitutional Responsibility Project will be organizing more than 50 events in nine states to pressure senators to consider Judge Merrick Garland, whom President Barack Obama nominated to fill the vacancy on the Supreme Court following Justice Antonin Scalia's death in February.

The group also touted a new poll conducted with Hart Research and the League of Conservation Voters, which found a majority of Pennsylvania voters, 56 percent compared to 37, want the Senate to hold hearings and a vote on Garland's nomination.

"Pat Toomey is seriously out of step with his state,” said Geoff Garin, president of Hart Research Associates.

Toomey is one of several Republicans who have met with Garland, but all but two GOP senators have refused to consider his nomination.

Outside groups and Senate Democrats have continued to push Republicans to act, holding rallies, highlighting polling data, and making floor speeches; they hope that public pressure will change GOP minds.

"In state after state we’re seeing support for these senators go down," said Cutter, one of several former Obama administration officials coordinating outside groups on the Supreme Court fight. “It’s not going to get any easier for them, It looks like Donald Trump is their presumptive nominee, which is making many of them nervous.”

In the Pennsylvania poll, pollsters surveyed 502 voters over the phone, including 100 registered independents, from April 20 to April 23. Aside from the independents, 48 percent of those surveyed were Democrats and 40 percent Republicans, to reflect statewide percentages.

The poll found that only 27 percent of voters were aware of Toomey's position that the Senate should not consider Garland before November's election. Once informed of his position, 57 percent overall, as well as 60 percent of independents, had an "unfavorable reaction."