On ‘thunderously absent’

On ‘thunderously absent’

The passage below is from A History of the Index by Dennis Duncan.

On 2 November 1965, New Yorkers went to the polls to vote for a new mayor. The race was a close one, with the Republican candidate John Lindsay coming out ahead of his Democratic rival Abraham Beame by 45 per cent to 41 per cent. Way off in a distant third was another candidate, William F. Buckley, Jr, a conservative intellectual and editor of the National Review. Buckley had always been a longshot for mayor. Back in June, when he announced his decision to run, the New York Times had poked ironic fun at the gulf between Buckley’s opinion of himself and that of the general public:

He regards New York as a city to be saved from crisis and, with his usual diffidence, himself as the man to do it. Whether New York is also ready for Mr. Buckley is another matter. Popular demand that he become a candidate has been thunderously absent.

I have questions concerning the bold-faced ‘thunderously absent’.

First, I think ‘thunderously absent’ is referring to ‘ironic fun’ in the previous paragraph. According to a dictionary irony means ‘the use of words to express something different from and often opposite to their literal meaning.’ And I think there is a huge difference or even opposite in meaning between ‘thunderously’ and ‘absent’. (Am I right?)

Then, I think ‘thunderously’ and ‘absent’ can be said to have a oxymoronic relation between them like ‘deafening silence’ (the former is not as definite as the latter, though). (Am I right?)

Thanks in advance.