Asking someone to lie to congress is a crime. Obstruction of Justice.
Trump lies every day and has all his life. It is reasonable to think he asked Cohen to lie to congress about the Russian Trump Tower because, to him, lying is normal.
I have read everything out there this morning, and Mueller investigators or him, personally, talked to employees of Trump's company. Those people would know if they were working on this project to build Trump Tower in Russia. Trump recently said he or his people, were communicating with Russia on this project so he could do it if he did not become president. That is one thing, but asking Cohen to lie to congress about it, is a crime.
Eventually, we will know what is the truth and what isn't.