U.S. Sen. Pat Toomey, a Pennsylvania Republican, broke ranks with the president on Monday in reaction to Trump's volley of "go back to where you came from" tweets.

“President Trump was wrong to suggest that four left-wing congresswomen should go back to where they came from," Toomey said. "Three of the four were born in America and the citizenship of all four is as valid as mine.

"I couldn’t disagree more with these congresswomen’s views on immigration, socialism, national security and virtually every policy issue," Toomey continued. "But they are entitled to their opinions, however misguided they may be. We should defeat their ideas on the merits, not on the basis of their ancestry.”

Toomey's Pennsylvania colleague in the Senate, Bob Casey, a Democrat, also commented on the tweets. "'Go back to your own country' is an ugly and deeply xenophobic sentiment rooted in the darkest periods of our history," Casey said. "The fact that our president has used these words is beyond the pale. Once again, his words make us less safe."

Valley Congressman Fred Keller, R-12, Kreamer, noted that "no country on the face of the Earth has provided more opportunity and freedom than the United States."

Every member of Congress, he said, takes an oath to defend and protect the Constitution, "but every day, members of the House Democrats fail to live up to that basic responsibility. Rather than promote anti-Semitic and socialist policies that are contrary to American values, Democrats in Congress should instead focus on their core responsibilities to their constituents and put American citizens first.”

Congressman Dan Meuser, R-9, Dallas, declined to comment.