The top Republicans and Democrats on the House and Senate Intelligence panels have said there is no evidence that Trump or aides were under surveillance.
The fact is that Trump lies. When caught in a lie, he blames it on the corrupt media. It was hard to counter that allegation, when it was the media reporting on why Trump was lying. However, now that Trump has started making allegations against foreign governments, it is harder for Trump create the impression that he is telling the truth.
When Trump lied on the campaign trail, people attributed his untruthfulness to salesmanship and puffing. Now that he is President, word do matter. If he tells a lie about a foreign government, that government will take offense. The consequences may be dire. Once credibility of the American President is lost, it may be impossible to regain the respect we once had.