ABC News’ David Chalian reports: Sen. Arlen Specter R-Penn., found himself yet again explaining his decision to break ranks with his party and support President Obama’s $787 billion stimulus package last month and he used dramatic language to do so. "I think we’re on the brink of a depression," Sen. Specter said to reporters in Harrisburg, PA on Monday. "I think that if we had turned it down it would have been repercussions world wide," he added. The moderate Republican was one of three members of his party in the Senate who crossed the aisle and voted in favor of the president’s plan. Sen. Specter, however, is the only one of the three up for reelection next year and facing the prospect of a serious primary challenge from fiscal conservative Pat Toomey of the Club for Growth. Mr. Toomey gave Specter a run for his money in the 2004 Republican primary when he narrowly lost to the incumbent by roughly 17,000 votes of just over 1 million cast. Sen. Specter is fully aware of the vulnerability on his right flank which may be why he painted such a dire and mysterious economic outlook when speaking with reporters today. "I knew that it would be politically perilous and I’ve been very blunt about it," he said. "Our economic problems are enormously serious, more serious than is publicly disclosed," Specter said without shedding any further light on what is being shielded from public view. ABC News’ Lindsey Ellerson contributed to this report.