I wouldn't equate Trump-Russia collusion with birtherism and other anti-Obama smears, for many reasons. Here are five.
* Russia systematically influenced internet forums, Twitter, etc, to help Trump in the 2016 election. This influence campaign is documented in the Mueller report, and several individuals and companies have been indicted. American intelligence says that Russia currently continues this activity.
* Mueller stated in his report that a lack of candor from several people interviewed as part of his investigation impeded the collection of evidence about coordination between Trump and Russia. Failure to bring charges against a person does not exonerate that person.
* Mueller did not set out to address the question of whether Trump "colluded" with Russia, and even if he addressed that topic in his report, there's no way for the public to know that, because the report is still heavily redacted.
* Manafort, Donald Jr., and Kushner met with representatives of the Russian government in Trump Tower. They did not disclose this to officials until Kushner was forced to revise his SF-86 because he failed to include information about his relationships with several key foreigners.
* Trump has sought election assistance from other foreign governments, including using missile defense as leverage over the Ukrainian president, as well as (according to Bolton) using a meeting with Xi Jinpeng to ask repeatedly for help with his re-election campaign.