I’ve been saying for a while that the Republicans could not pick a worse time to play their little game of debt ceiling chicken with the economy still fragile coming out of the pandemic. Now, it may be suicidal. Catherine Rampell writes: A plea to lawmakers: If it was a bad idea to threaten default on U.S. debt before, it would be astoundingly, colossally idiotic now. Recent financial-market turmoil — in regional U.S. banks, as well as some of the larger European institutions — suggests there might be much more fragility in the financial system than previously understood. In a sane world, politicians might respond to this new information constructively. They might, for instance, figure out what they could do to ensure that financial regulators detect vulnerabilities at significantly sized banks sooner. Politicians might also take some modest actions to combat inflation themselves, so that less of the burden of dampening demand falls on the Federal Reserve’s interest-rate increases — which are part of the reason we’re seeing stresses in the financial system today. Unfortunately, that sane world does not appear to be the one we live in. Faced with the second-biggest bank failure in U.S. history, lawmakers retreated to their predictable partisan talking points. Democrats blame a 2018 rollback of “stress test” requirements on small and midsize banks. While this might plausibly have contributed to Silicon Valley Bank’s collapse, we still don’t know forcertain; bank supervisors might have spotted the problem on SVB’s balance sheet even without those requirements, given that the bank was relatively open about its poor risk…