I hear you, but the options are letting the President have his stupid racist symbolic gesture so he can use it to try to give us four more years of this, or not doing that and letting the tantrum resume. The third option of not letting the President throw his tantrum because there are enough Republicans who would rather not to override a veto isn't going to happen because McConnell isn't going to let it.
I think you are correct in assuming that every move he makes is geared towards ensuring he's re-elected. If somehow his approval rating held steady during the shutdown, he'd have never re-opened the government. Given that he loses in 2020, he'll be indicted for felony campaign finance violation on January 20th, 2021, only months before the five year statute of limitations expires. "Campaign like your life depends on it" is an apt phrase....his stupid racist symbolic gesture so he can use it to try to give us four more years of this...