WASHINGTON — The House speaker, Paul D. Ryan, has expressed no particular opinion on the stop-and-frisk police tactics advocated this week by Donald J. Trump. He does not have any certain thoughts about Mr. Trump’s repeated praise of Vladimir V. Putin. He sort of suggested that Mr. Trump should release his tax returns, but what he really meant, it seems, is that candidates in general should do so. Then again, he said that he would “defer” to Mr. Trump on the decision.

The man who once pointedly withheld his endorsement of the Republican presidential nominee, who called a statement of Mr. Trump’s “the textbook definition of a racist comment,” who questioned whether Mr. Trump shared his party’s “values and our principles on limited government, the proper role of the executive, adherence to the Constitution,” has suddenly gone taciturn.

Since Congress returned from its seven-week recess this month, Mr. Ryan has largely refused to answer any question about Mr. Trump, from his policy proposals and campaign antics to his latest controversial statements.

At his weekly Capitol Hill news conferences and in other interviews, Mr. Ryan generally redirects questions about Mr. Trump to his own ideas. “Look at what the House Republicans have offered in our Better Way,” Mr. Ryan often says, referring to the House policy platform, in a live form of an outgoing phone message.