Lincoln was never a senator. He was a one-tern congressman. He ran for the senate against Stephen Douglas, but lost.
And in general, Presidents whose only experience prior to the presidency was serving in the Senate have been some of our worst presidents. NONE of the presidents who previously served in the Senate could be grouped into a list of our greatest presidents. (Some would argue that JFK should be considered a great president, but I think he is considered in that way simply by virtue of his assassination - it is hard to point out any great and lasting legacy from his presidency other than Vietnam and the Cold War.)
A fair assessment, I think, is that JFK started out as a poor president and was evolving into an above average president at the time of his assassination.
He didn't understand the danger of Castro, but he did understand the value of tax cuts. On the average, he was a mediocre president on par with Harry Truman which made them the best Democrat presidents of the 20th century.
If forced to choose between JFK and Truman, I'd pick JFK since throwing Cuba to the Communists was far less serious than throwing China to the Communists.
I totally agree. The Senate is nothing more than a clubby, House of Lords environment where standing your ground is seen as gauche. Most of Ted Cruz' contemporaries -- dem or GOP -- would love nothing more than to bounce him out of their comfy little outfit.