Loss is worse than risk. Cruz was probably fed the line by some haphazard researcher.

…in which the Churchill remark was made. In 1940 Churchill was defending the all-party coalition he had brought together in defense of the nation. One of those parties (Labour) was intent on persecuting the Conservative and some Liberal politicians who had led Britain to its current state.

There was nothing to gain in that, Churchill said, and he had as good a reason to blame the Conservatives as anyone on the Labour side. For example, Labour had steadfastly supported appeasing Hitler until 1939, and had voted against conscription. Like the Labour critics of 1940, Sen. Cruz seems to spend much of his time opening quarrels between the past and present.

Churchill deployed this famous passage again at the Conservative Central Council meeting on 28 December 1945. Of course, by then, much had changed. The war was won. Labour was in power. Churchill and the Conservatives were in opposition. Now Churchill was imploring his party to accept a new challenge—a domestic one.  So what he said in 1945 is arguably more relevant at the moment:

​As I said in the House of Commons in June, 1940—that breathless moment in our existence—”If we open a quarrel between the past and the present we shall find that we have lost the future.” Let us advance then into the future with the same confidence and dogged determination which all the world admired in those days when our national life and, may we not say, the freedom and glory of the world were at stake. If every measure is taken, as it should be taken, if every effort is made, as it must be made, if every act of comradeship and audacity is performed, as it will be performed, there is no reason why we should not lead our country out of its hideous lapse and error in domestic affairs, just as we in Britain did in the great world struggle, of which for a whole year we bore the brunt alone. Here, happily, we have not got to fight the terrible foreign foe, but only to regain the goodwill and revive the morale of our own fellow-countrymen who came such a melancholy cropper at a moment when the opportunities of Britain were so great and our tasks so hard.