More for the grammar police

Thanks to the grammarians who replied to the last post. Not the Last Post, pedants.

There are other perplexing grammatical issues washing around bollocksville at the moment. Can someone - probably not that Pauline nong - explain what 'doubling down' means. It's yet another awful yankism that we seem to have adopted.

The SMH is the guilty party, In an article concerning three federal ministers' wanton disregard for the separation of powers, it stated, "Fellow crossbencher David Leyonhjelm also doubled down on his criticism after last week labelling the judiciary as "dear little daffodils"."

So can someone reach out to me going forward?