The Senate's modest milestone
The bad news: that number is two. Out of 100.
Also, both Sen. Tim Scott (R-SC) and new Sen.-designate William Cowan (D-MA) were appointed by governors, not elected. Scott replaced Sen. DeMint when he left to lead the Heritage Foundation, and Cowan was just announced as the replacement for Sen. Kerry, who's about to become secretary of state. That doesn't make Scott and Cowan any less legitimate as legislators, but it also doesn't give their states' voters a milestone to take credit for.